Archive of Our Own

Light.

Blinding-hot-white. A burst so intense it seared behind his eyelids, like lightning cracking just before the sky splits open.

Then… silence.

When the brilliance faded, Katsuki stumbled forward, one hand raised instinctively to shield his eyes, blinking hard against the sudden daylight.

Everything was wrong.

The familiar hush of the summer night had vanished, replaced by a too-vivid blue sky and the harsh glare of the morning sun. Katsuki turned sharply, scanning his surroundings.

Monoma was gone.

He’d been right there. A smug smirk on his face, one hand lifted, a gloved finger etching some weird semicircle into the air.

And the second that motion completed, everything changed.

Pressure, like a deep thrum under the skin. A low buzz at the base of Katsuki’s skull. And then… there was light. 

Everything disappeared, swallowed up in that blinding glare.

What the hell.

How the fuck had he even ended up in this mess? Goddamn Monoma. He’d sounded so desperate on the phone, barely minutes ago.

“Hey- look, I know it’s Midoriya’s birthday and you’re probably busy, so feel free to blow me off-” Monoma’s voice had been frantic, shallow with panic. “I’m dealing with a villain… way above my pay grade. I can’t hold her on my own. Can you back me up?”

And Katsuki, fucking idiot that he was, had said yes. Of course he had. Monoma might’ve been a pompous motherfucker, but even with all his swagger, Katsuki knew he wouldn’t be calling for help unless he was in some serious shit. He was irritating as hell, yet beneath all that flashy bravado, his intentions were usually good. Katsuki could see that, no matter how often he wanted to blast his head, ridiculous clock earrings and all.

So Katsuki had rushed to change into his hero costume (the one that left his shoulders bare, it was so damn hot out there), and bolted to the coordinates Monoma had sent him.

To be fair, he’d wanted that excuse. Anything to get away from that goddamn izakaya. Any-fucking-thing.

Not that it mattered now.

There were more pressing issues at the moment.

Like… what the fuck had just happened?

Katsuki turned slowly, scanning the area.

A low red-brick wall ran along the side of a path lined with trees, their leaves shifting gently in the breeze. He caught the faint scent of salt on the air; ocean wind threading through the branches.

He was definitely still in Musutafu.

But something was off. Well… besides the obvious fact that night had just snapped into day like someone had flipped a switch.

His eyes darted, picking apart the scene.

That’s when the pieces started falling out of place.

First was the ramen shop he remembered shutting down over ten years ago standing tall and grimy, its faded sign still proud against the wall. Then, across the street, that old Japanese restaurant, the one that had been gutted and turned into a Western retail chain, still stood untouched. Even that ugly concrete building they’d torn down to build the new multiplex was still here, like nothing had ever happened.

Katsuki stared, breath lodged somewhere between his chest and throat. His pulse kicked faster. Logic tried to insist this was impossible, but it bent under the truth of what he was seeing. 

No fucking way.

Was this… the past?

Had Monoma actually thrown him into the goddamn past?

“Shit,” he muttered, swiftly reaching for his phone. First instinct: scream at that bastard through every known app. What the hell was he thinking? Why the fuck had he set him up? Was it some kind of sick prank?

But of course… nothing. The signal bars were there, but any kind of message he tried to send failed miserably.

He hissed between his teeth and shoved the phone back into his pocket.

Fine.

He’d figure it out himself.

He stalked forward, boots striking pavement hard enough to sting his heels. His jaw locked, teeth grinding as he shoved back the panic clawing at the edges of his mind. He needed a plan. He needed facts he could punch into shape. A lead, a thread; anything solid he could hold onto that might explain what the hell had just happened, or what the hell he was supposed to do next.

When the fuck even was this?

Where the hell would his past self be?

And…

Where would Izuku be?

Heat crawled under Katsuki’s skin at the thought. His eyes swept the street around him, and it hit him that his feet had carried him along a path burned into old muscle memory; the same route he used to walk to middle school.

Something shifted in the air, as though the world had tilted to point him forward.

That’s when he saw him.

A few meters away, standing perfectly still. 

Green messy curls, stirred by the breeze. Freckles, all those freckles, still unmarred, scattered across his cheeks. Smaller than Katsuki remembered, slender in a way that twisted something low in his chest. His eyes wide, stunned, locked right on him.

Katsuki’s heart missed a beat, then roared back to life in his chest.

Every thought stopped. Everything else disappeared.

“K-” Izuku’s voice cracked under the strain of confusion.

Katsuki wasn’t faring much better. Sure, he knew this was Izuku. But knowing it didn’t answer a damn thing, not yet.

His throat pulled tight. He looked once more; really took it in.

Notebook clutched close against his chest. That same yellow backpack, too big on those tiny shoulders. Middle school summer uniform: short-sleeved white shirt, black slacks. Arms too thin, bracing as if he were afraid.

Was he afraid… of him?

Katsuki’s stomach twisted.

Suddenly, the past he’d fought so hard to bury was staring right back at him. Time hadn’t softened it; years of striving to change hadn’t made it just a distant memory. It was there now; untouched by any apology, unchanged by sacrifices, by blood spilled, by bruised knuckles earned in the fight to become someone better.

No matter how far he’d come, this part of their story couldn’t be rewritten. And now, face to face with a version of Izuku still carrying the weight of all of it…

He felt everything again.

He had never forgotten. Not one shove, not one word spit out from fear. Every insult, every moment he’d let his anger rot into something cruel; it was all there, echoing now in the way Izuku stood. In the tension around his shoulders. The way his fingers pressed tighter around that notebook. The look in his eyes.

This Izuku didn’t know what was coming. Didn’t know how they’d end up standing side by side. Didn’t know how hard Katsuki would fight, or die, to become the hero Izuku believed he could be.

He only knew what had already happened.

Yet, this Izuku didn’t run.

Of course he didn’t. 

Katsuki should’ve known. Izuku never ran from him, not even when things were at their worst. 

If anything, he’d never stopped trying to reach him.

So, this Izuku stepped forward, hesitant. Every motion looked measured, as if even a breath out of place might collapse the distance between them.

“Kac-” he whispered again, eyes moving across Katsuki’s face, searching for something that made sense.

Katsuki didn’t move. Not out of fear; but because he just didn’t know how to react, how to act in this situation. 

“It can’t be,” Izuku said, voice barely audible. “You can’t be Ka… Kac-”

What was he even supposed to say to that?

Yeah, no shit, he was Kacchan. 

Izuku’s Kacchan. 

But how the hell was he going to explain this?

He didn’t even know what this was. He had no idea how he got here, what the hell Monoma had done, or whether it could be undone. Whether one wrong word might break something open; rip through the timeline, ruin the future they’d fought tooth and nail to protect.

But, lucky for him, he didn’t need to explain much.

Izuku had always been a goddamn clever nerd, after all.

“Wait…” His mouth fell open, eyes rounding, a breath catching somewhere between disbelief and awe. “No way-are you… future Kacchan?!”

Katsuki exhaled sharply, tension loosening from his shoulders for a fraction of a second. The weight in his chest didn’t go away, but hearing those words made something shift inside.

“Yeah,” he muttered, rubbing the back of his neck. “Guess that’s one way to put it.” God. Why did he suddenly feel awkward? Embarrassed, even?

Izuku didn’t reply right away. He just stared; like Katsuki had stepped out of a spaceship or turned into some kind of alien. His gaze swept over him in stunned silence, devouring every detail; his face, his gear, his costume, the lines of muscle he hadn’t had before. 

Katsuki blinked. Watched Izuku’s breath start to quicken; shallow, uneven. Watched the way his throat bobbed with a hard swallow. His chest was rising too fast now.

And then…

A small, red streak of wetness appeared beneath his nose.

Katsuki’s entire body tensed.

“The hell?!” he barked, stepping forward without thinking, his heart already kicking into overdrive. “Are you bleeding?!” 

Izuku let out a strangled gasp, one hand flying to his face, the other clutching his notebook so tightly his fingers shook. “Wh- oh no! No, no, no-”

Color rushed over him, flooding up his neck, across his cheeks, all the way into the tips of his ears. Katsuki could’ve sworn steam was starting to curl off his skin.

“Oh my god,” he blurted again, higher this time. “Oh my god!!”

Izuku wouldn’t look at him. His eyes bounced from the pavement to the sky to his own blood-smeared fingers, desperate for something, anything else to focus on.

Katsuki stood there, too stunned to move.

What the hell was even happening?

Izuku looked wrecked. Flushed to the ears, cheeks blazing. Red… so red.

Fuck.

Katsuki didn’t want to make the connection. Because this wasn’t the same. It wasn’t.

But it hit anyway. He couldn’t help it, couldn’t think past it. Because it was all that had been circling his mind lately.

Because he’d just seen Izuku blushing.

Minutes ago.

Back at the party.

Izuku’s goddamn birthday.

Katsuki sitting at the edge of the table like some guest at someone else’s life. He hadn’t even wanted to go that night. Knew what was coming, knew what he’d see.

But he had to be there.

Because it was Izuku.

And Izuku, damn him, for the first time in years, hadn’t sat beside him.

No. He’d been next to Uraraka. Laughing, leaning in, shoulders brushing. Heads tilted together like they shared some secret the rest of them weren’t meant to hear. Like some panel torn from a shojo manga.

They looked so fucking easy.

Katsuki had ended up next to Kirishima and Kaminari. They’d been joking about some dumb viral video, talking about the latest popular manga, making plans for the weekend, and shit like that. Katsuki had barely heard a word.

His drink had gone warm in his hand. Their voices blurred into static.

Because he couldn’t stop watching.

Izuku and Uraraka. That damn nerd and Round Cheeks.

Katsuki had told himself it was the booze. That soft flush on Izuku’s face? The slight shine in his eyes? Just alcohol. Just ambient light. Just his own goddamn paranoia, eating him alive.

He wasn’t going to read into it.

He refused to read into it.

Izuku and Uraraka hadn’t seen each other in years. She’d just reappeared out of nowhere, right around the time Izuku went back to hero work part-time. Of course they’d reconnect. They’d always been good friends. They had history, shit to talk about.

And yet…

That weight hadn’t left his chest for days. That crushing pressure that told him something had changed, that maybe he’d lost something he never fully had.

And fuck, Katsuki regretted so much what he’d said that night.

“If you treat everyone like they’re special, no one really is.”

He had meant it as a wake-up call. A desperate attempt to get Izuku to stop stretching himself thin for everyone else and finally put himself first. But of course, the idiot had taken it the wrong way. Katsuki hadn’t meant (god, of course he hadn’t meant) for Izuku to run off after Uraraka.

But that was exactly what that damn nerd did, for whatever fucking reason.

And now… 

Now Katsuki was here. Back in the past, apparently.

And that stupid version of adult Izuku was gone.

In his place stood a scrawny, skittish kid with blood on his upper lip and big eyes fixed on him like he’d just seen a ghost. Not that any of this made a whole lot more sense to Katsuki either.

“Izuku,” Katsuki snapped, “are you good?”

Izuku froze. Blinked.

“I-Izuku?” he echoed, like the name didn’t belong to him.

Shit.

Katsuki’s stomach dropped. Of course. This Izuku wasn’t used to hearing his own damn name from him.

Fuck, it had been so damn long that he completely forgot.

“Deku,” he corrected quickly, awkwardly. “I meant Deku! You-you shitty nerd!” 

Izuku’s eyes somehow widened even further (Katsuki wasn’t sure how that was physically possible) and for a second, it genuinely looked like he might pass out. His breathing hitched.

“Sure you’re Kacchan?” he whispered, barely audible. “You’re… worried about me? And your- your voice…”

Katsuki scowled, something twisting in his chest. “What about my goddamn voice?”

Izuku hesitated, eyes flicking to Katsuki’s mouth, then darting away again. His throat worked through a hard swallow, and the flush in his cheeks deepened until his whole face looked like it might combust.

“It’s… softer,” he mumbled.

Softer? What the hell was that supposed to mean?

Katsuki didn’t get the chance to ask. Because-

Drip.

Another fresh line of blood slipped from Izuku’s nose.

“Fucking hell,” Katsuki muttered, already stepping forward.

Izuku yelped, slapping his hand to his face again. “Oh-no-no-no!” he squeaked. “I stained my shirt! On my birthday! Damn it!!”

Birthday?

So this was his birthday in this timeline too. Katsuki filed it away instinctively; a tiny scrap of concrete information in a sea of absolute insanity.

But something wasn’t adding up.

Because Izuku… he’d never been sick on his birthday. Never hurt, not once. Not even as a kid. Katsuki would’ve remembered something like that; any incident, any scraped knee, bleeding nose or hospital visit, but there had never been one. Izuku’s birthdays had always been normal and ordinary.

Fuck. Wait. 

Why the hell did Katsuki remember so much?

Every birthday, every damn detail. Even the ones where they hadn’t spoken for months. He remembered the cake Izuku’s mom used to bake, the All Might wrapping paper, the years they’d celebrated at UA, the way Izuku’s eyes lit up when someone showed up for him.

He remembered every-single-goddamn-birthday.

And holy shit.

Had he always been this far gone?

Katsuki groaned internally.

“I-I have to go!” Izuku stammered, still covering his nose, already moving in a flustered mess of limbs. “I need to clean this up before it dries!”

“Hey, wait-”

Katsuki barely had time to think, let alone react, before Izuku’s foot caught on something; probably a stupid pebble, or a crack in the damn pavement. Whatever it was, it didn’t matter, because one second Izuku was walking, and the next-

Wham.

Katsuki hit the ground. Flat on his back.

And Izuku…

Izuku landed right on top of him.

Straddling his thigh.

And…

And.

Oh fucking god.

There was a pause.

A heavy, horrible, horrifying pause.

Because Izuku’s groin was pressed directly against Katsuki’s leg. And…

Yeah.

There was no mistaking it.

Fuck.

Izuku was definitely, undeniably, hard.

Katsuki registered it all at once: the pressure, the angle, the friction of Izuku’s legs bracketing his thigh.

They didn’t move. 

Just two idiots frozen in the most embarrassing position imaginable, eyes locked, cheeks burning.

Izuku looked like he was three seconds away from either crying, exploding, or ascending into another plane of existence out of sheer mortification. The hand not gripping the notebook hovered helplessly near his face, nose still dripping, a weak squeak escaping his throat as he tried (and failed) to mop up the mess with his bare forearm.

Before Katsuki could even begin to figure out what the fuck to do next, Izuku scrambled to his feet like Katsuki had burned him. He didn’t say anything, didn’t even look his way; just let out some frantic, garbled noise and, with a speed he shouldn’t have possessed without One For All, bolted.

He vanished around the corner in under two seconds, legs flailing, arms windmilling like a tornado running purely on adrenaline and shame.

Katsuki stayed where he was, still sitting in the dirt, with his thigh faintly tingling from the contact.

He ran both hands down his face, groaning into them, hoping the ground might just open up and do him a favor.

Did that goddamn nerd seriously get a boner just from looking at him? What the hell? 

So now he wasn’t just stuck in the past with no clue how to get back to his timeline. No. Now he also had to deal with this ridiculous, embarrassing bullshit.

There was a sharp, gnawing certainty in his gut that talking to Izuku was the key to understanding whatever quirk had yanked him here in the first place. But how the hell was he supposed to do that if Katsuki’s mere presence reduced Izuku to a babbling, bleeding (and apparently horny) mess?

He sighed, getting to his feet again. Maybe he could try talking to his own past self instead? Yeah. Great idea. Surely that would be a chill and productive conversation, knowing how fucking charming he used to be. 

Or maybe All Might? Jeanist? Aizawa?

They still hadn’t met him at this point in time, but hell, maybe one of them could help him get a grasp on the situation if they were willing to listen.

God. If he ever got his hands on fucking Monoma…

The thought was just starting to shape into a satisfyingly detailed revenge fantasy when the air shimmered again.

That light.

Blinding, burning straight into his retinas.

And just like before…

Everything snapped.

A sharp, sudden shift. One moment he was cursing Monoma in the middle of the street, and the next… blinding light.

When it all settled again, Katsuki squinted into the brightness, his vision swimming as the world around him took shape.

He was in a room.

Blue. Red. Yellow. White. Blue. Red. Yellow. White. Blue. Red. Yellow. White.

Everywhere.

Blue. Red. Yellow. White. Blue. Red. Yellow. White. Blue. Red. Yellow. White.

Katsuki didn’t even have to think about it.

All Might figures crammed onto every surface: shelves, desk, nightstand. Keychains dangled from drawer handles. Posters wallpapered the room from floor to ceiling. There were books, DVDs, plushies. Even the bed had a big, bright All Might duvet cover. And the curtains, god help him, were All Might-themed too.

There was no mistaking it.

This was Izuku’s room.

A room he hadn’t seen in years, not since they were kids.

Katsuki looked around. He seemed to be alone; no sign of Izuku or Auntie Inko anywhere.

His eyes landed on the daily calendar (All Might-themed, of course) sitting on the desk, marking today’s date and year.

Sunday, July 15th.

Izuku’s birthday again?

Was he seriously bouncing through Izuku’s birthdays?

Judging by the calendar, this was their first year at UA.

He remembered this one, too; how could he not? Class A had thrown a party for Izuku that afternoon in Musutafu. That was Izuku’s first birthday surrounded by people who genuinely cared; people who he could call friends.

Katsuki hadn’t gone, though; wouldn’t even consider it. The sight of Izuku at that time only made him sick. He’d convinced himself that he didn’t give a shit.

But the truth was he always had, in some messed-up, sideways kind of way. Even when he couldn’t handle it. Even when all those feelings twisted into rage or came out as cold, pointed silence.

He shook his head and turned to leave. At least now he could try to find Aizawa or All Might without having to explain who the hell he was. Maybe he could even track down that obnoxious teenage version of Monoma and offer him a free preview of the beating his adult self had earned.

But then…

Something stopped him.

A sudden breeze slipped in through the open window. It stirred the air. Rattled a keychain. 

Shuffled the pages of a notebook on the desk.

Katsuki stiffened.

And this time… he had to think about it.

He blinked. Rubbed his eyes. Looked again, squinting.

It wasn’t a sketch of All Might. No hero notes, no training strategies, no combat theories.

There were…

Dicks.

So. Many. Dicks.

Izuku had never been a particularly good artist, but, holy shit, the effort in these was something else. Dicks were drawn from every possible angle. Front, side, top, three-quarter. Some shaded like full-on figure studies, complete with contrast and crosshatching. Others diagrammed with arrows, notes, and numbered labels in the margins.

Katsuki’s jaw slackened. He leaned in, unable to stop himself, and started reading despite every rational part of his brain pleading with him to walk away.

Right at the top of the page, in neat handwriting:

Personal notes - for research purposes ONLY!!!

Based on regular visual exposure during shared locker room and bathing facilities over the years (approx. 97 documented instances since age 10), I can reasonably confirm Kacchan’s flaccid penile length averages around 9.1 cm. (Notably consistent. Minimal retraction in cold water = Kacchan is always amazing.)

Personal baseline: 7.9 cm flaccid (average, neutral temp). Erect: 15.2 cm (week 8 log).

Hypothesis:

• Kacchan’s erect size likely ranges from 16-19 cm, potentially more under high-peak arousal (see fig. 2 and fig. 4)
  
  
• Girth estimated at 14-16 cm circumference (see fig. 5 and fig. 13).
  
  
• Shape: possible upward curve. Distinct dorsal vein patterning (see fig. 3).
  
  

Pubic hair: early development. Dark blonde. Trimmed? Groomed intentionally? Naturally neat? (see fig. 7)

Testicles: still pending proper analysis (limited visibility).
Note to self: find a plausible way to investigate further.

 

Katsuki stared.

And kept staring.

His brain short-circuited; an overload of static and impulses; too many neurons trying to scream at once.

Heat roared in his ears, burning down his neck, setting his face on fire.

His heart was pounding.

He blinked at the pages like the drawings might jump out and start talking to him; start explaining themselves or some shit.

What the fuck.

What the actual fuck?????

Katsuki’s gloved hand shook as he flipped the page, hoping to find some excuse for what he was seeing. Maybe it wasn’t what it looked like. Maybe it was just another one of Izuku’s weird obsessions; a messed-up way of studying heroes. Some dumb attempt to break down bodies for training, or a detailed catalog of the class.

Yeah. Sure. 

He wished.

The next spread was equally insane.

More drawings.

Hyper-focused, maddeningly detailed drawings. Abs. Pecs. Biceps. An ass.

And not just anyone’s.

His.

He knew because there it was his name, again, scrawled in the margins.

Katsuki’s eyes widened in disbelief. His mouth opened, but no sound came.

And then-

As if the name he’d just read leapt from the page straight into his ears…

“K-Kacchan???”

The voice sliced the silence like a blade. Behind him. Small and horrified.

Katsuki went still, every muscle locked. The notebook hung open in his hands, pages fluttering slightly. 

Izuku stood in the doorway, pale as a ghost, eyes huge with panic and disbelief. His mouth opened, closed, opened again; like he couldn’t decide whether to speak or combust on the spot.

Katsuki wished, prayed, begged, that the goddamn time-travel light (or wormhole, or glitch in the cosmic code, whatever the hell it was) would just come back and drag him out already.

But it didn’t. Of course it didn’t. The universe fucking hated him.

Before Katsuki could so much as blink, Izuku bolted forward (stupidly fast, which made sense this time, he had One For All at that point) and yanked the notebook from Katsuki’s hands and hugged it to his chest so tight his knuckles went white.

Katsuki’s brain wouldn’t restart. His eyes still burned with the memory of all those damn dicks and abs and his own ass sketched in black-and-white lines he’d never unsee.

But then… Izuku stared at him. Just stared. His throat worked around a swallow. He looked like he might speak, but nothing came out. Another swallow.

Katsuki, still embarrassed, braced himself, half-expecting another round of Yeah, I’m future Kacchan bullshit. He opened his mouth to snap at him, but Izuku beat him to it.

“I- I just-,” he squeaked, voice pitching high enough to crack.

His head dropped forward, curls slipping over his eyes. His shoulders trembled.

“What the fuck?” Katsuki muttered.

“I- I can’t-” Izuku choked out, shaking his head, shoulders trembling harder now. “I can’t believe it.”

And then he just lost it.

He erupted into full-on, breathless laughter, clutching the notebook to his chest as if it were life support. The sound spilled out in harsh bursts, cut with hiccups and the occasional snort.

It wasn’t exactly happy. It carried an edge balanced between disbelief and something painfully close to self-loathing.

Katsuki blinked, stunned. Out of everything he’d braced for (screaming, stammering, maybe even a quirk blast to the face), this hadn’t made the list.

“…Seriously? Now? You again??” Izuku gasped through laughter, tears beginning to form at the corners of his eyes. “What the hell is wrong with me??”

Katsuki narrowed his eyes, baffled and increasingly unsettled. “…Izuku, what the fuck??”

That only made it worse. Izuku doubled over, wheezing as the laughter spiked again. “Izuku?” he repeated, voice rising with disbelief. “Wow. It’s even worse than I thought!”

Katsuki winced. Goddamn it. He’d slipped again; he’d called him Izuku. He wasn’t supposed to do that yet. It was still Deku, back then.

But before he could correct himself, Izuku’s expression shifted. The laughter dropped entirely from his face. He blinked through the lingering tears and looked Katsuki straight in the eye.

“That’s enough,” he said quietly; but steady. “The others are waiting for me. Kacchan won’t be there. I know that. And that’s okay. I don’t have to expect too much. It’s my party. With my friends. All Might’s coming too. All Might!! I should only be grateful.” A breath hitched in his chest. His grip tightened on the notebook. “Why must my brain ruin everything now?”

Katsuki stared, incredulous.

“Wait. You think I’m a fuckin’ hallucination?”

“Please don’t say anything else.” Izuku’s voice was rising now, every word laced with unraveling nerves. “Just… get out of here.”

“Izu- Deku, what the fuck?”

“Nice try,” Izuku snapped, slamming the notebook down. “Get. Out.”

He grabbed Katsuki by the arms (and holy shit, he was so fucking strong already) and started pushing.

“Deku- hey! Hold on!”

But there was no holding on.

In one fluid, brutal shove, Izuku pushed him out into the hallway. The door slammed shut hard enough to make the frame rattle. A second later: the snick of a lock.

Katsuki stood there, blinking at the All Might-themed door tag stamped with “Izuku.” His breath came short. His mind spun.

“…For fuck’s sake,” he muttered, dragging a hand through his hair.

At this point, he wasn’t even sure if he’d landed in the past anymore. The whole thing had been too surreal, too absurd to make sense. Fourteen-year-old Izuku getting a nosebleed and a boner just from seeing him? This Izuku sketching anatomically accurate, hyper-detailed drawings of his body like he was some kind of subject in a hero-themed erotic study?

No way. No fucking way.

Maybe these were alternate timelines. Hallucinations. Fever dreams. He didn’t know. His thoughts were unraveling so fast that logic didn’t even stand a chance.

And then, it happened again.

That light, blinding, buzzing at the edge of his vision, swallowed him whole before he could even curse it. He barely flinched this time; his body was starting to memorize the rhythm of being ripped through space and time without warning.

Not that it made it any less fucked up.

Still… he was almost grateful for it. Anything to get the hell out of that room, away from that notebook that now was forever burned into his brain. He hated himself for it, but he couldn’t decide if he felt horrified, weirdly flattered, or, god help him, even turned on by all that embarrassing bullshit.

But now that he knew what kind of madness these time jumps could drop him into, what the hell was waiting next?

Fuck, he wasn’t sure he wanted to know.

The light dimmed.

He stood still, senses straining in the quiet.

A room, again. 

This one was different. Familiar. So, so familiar.

The air was clean and dry, with a faint echo of dust and old furniture. Everything was in perfect order. The bed was tightly made, the desk pressed flush against the wall, the closet door shut. The whole space was dark, lit only by the glow of a streetlamp leaking through the blinds. 

It was his old dorm room at UA. No doubt. 

The layout was identical. The furniture hadn’t moved a bit since high school. But it was empty. No stack of worn training manuals. No posters, no notebooks, no CDs. Nothing to prove he’d ever lived here.

Before he could make sense of the situation, the doorknob twisted.

Katsuki stiffened, instinct kicking in.

The door opened slowly. Someone stepped inside, switching the lights on.

Izuku, of course.

But not the nervous, blushing teen from earlier. This version was older. Late teens, maybe twenty. Still boyish, but his jawline was more defined (it wasn’t much, but Katsuki could tell the difference), his frame more solid. He wore a crisp white shirt and dark blue slacks. The top buttons were undone. His sleeves were rolled carelessly to the elbows. His cheeks were tinged pink.

Had he been drinking?

“Oh, already?” Izuku said, pausing in the doorway. He sounded surprised, though his eyes told a different story: calm, the faintest hint of something smug tugging at his lips. “Heh. Perfect. Finally something nice for my birthday.”

Katsuki blinked. “Huh?!”

That was all he managed before Izuku was on him.

Hands on his chest, a shove. Katsuki stumbled back, legs hitting the edge of the bed; and then he was down, sprawled across the covers with Izuku following, climbing over him with the ease of someone who had absolutely no doubts about what he was doing.

And then he kissed him.

He fucking kissed him.

For half a second, Katsuki’s brain refused to boot back up. Then his hands flew up, shoving Izuku hard by the shoulders.

“W-what the actual fuck?!” he blurted.

Izuku pulled back just enough to look at him, lips parted, breathing hard. Amusement sparked in those green eyes, edged with something darker.

“Playing hard to catch this time?” he murmured. He leaned in closer, breath ghosting over Katsuki’s cheek. “That’s hot.”

Then his tongue swept out; a slow, wet lick tracing the curve of Katsuki’s ear.

Katsuki flinched, heat blooming across his face. “W-wait… what the hell is this?! What are you even doing?!”

He tried to twist away, but Izuku’s grip was like iron. Both hands pressed into Katsuki’s shoulders, holding him there like Izuku had every right to be on top of him.

Izuku just hummed contentedly and leaned in, nosing against the side of his neck. One hand slid up, fingers deftly brushing the top of Katsuki’s collar.

He found the zipper.

It hissed open, the sound absurdly loud in the quiet room. Katsuki’s skin prickled with every bit the zipper revealed, collar loosening as Izuku dragged it halfway down his chest.

“So many questions,” he said, lips grazing skin. “You’re such a cute, restless dream tonight.”

Dream?

Katsuki’s mind reeled.

Izuku thought this was a dream!?

First, high-school Izuku hallucinating him, now this one dreaming about him. The way this Izuku was acting… he seemed way too familiar with having fantasies like this.

And why the fuck were they in his old room at UA?

Katsuki didn’t have much time to think, though.

Izuku was already mouthing at his throat, fingers skimming along the lines of muscle visible beneath the half-unzipped top. His hand slid higher, seeking out the hidden button inside Katsuki’s neck guard; the one designed to break the guard down into nano-particles and pull it back into the rest of his costume.

How the hell did he even know that existed?

Sure, by that time Katsuki had already introduced nano-particles technology into his gear. But Izuku wasn’t supposed to know about that fucking button. What a damn stalker.

And while Katsuki’s brain groped desperately for logic, his body was already betraying him without a second thought. 

His dick was definitely reacting. Shamefully fast, too.

How could it not, with Izuku stretched out over him, tongue grazing the hinge of his jaw, breath hot against his cheek? Every bit of him felt branded by touch; too much and not enough at once.

It felt wrong.

It felt so fucking wrong.

And yet.

How many nights had he imagined this very thing? How often had he jerked off to the thought of being pinned down by those thighs, gripped by those hands, touched by that mouth in all the places that would tear him apart?

And this Izuku… he wasn’t some kid anymore. He had to be at least twenty now, maybe already a couple of years into teaching, if Katsuki judged right. 

“You’re so hard already,” Izuku breathed, rubbing himself against Katsuki’s aching cock through layers of fabric. His own arousal was just as blatant, grinding hot against him. “You’re amazing. You feel so real this time.”

“Y-yeah, no shit,” Katsuki muttered, knuckles tight on the sheets.

“Mh? What do you mean, Kacchan?” Izuku half-smiled before whispering, his voice cracking slightly, just enough to betray something raw beneath the haze. “Trying to make me think you’re real? Hah. You’re older than the real Kacchan. You’re always older, in my dreams.”

And then he started moving.

His hips rolled in steady, hungry thrusts against Katsuki’s, dragging friction until it almost burned. Fabric shifted, caught at all the right places. Katsuki’s head fell back, a groan slipping free as heat surged through his gut.

Izuku’s lips found the crook of his neck, open-mouthed, biting hard, sucking at his skin like he wanted it marked. And he’d definitely leave a mark. Katsuki couldn’t hold back the noise that slipped out of him: a loud, desperate whine that had him shaking.

Holy fuck.

His cock twitched hard inside his pants, body already close to the edge, the feeling creeping in fast and impossible to stop.

“W-wait-fuck, I’m gonn-” he gasped, breath caught, but Izuku didn’t ease up. His mouth moved feverish against his throat, hips moving in desperate, broken rhythm. The sounds he let out were ragged and raw; wanting, aching.

It was messy and too much and Katsuki was seconds from-

And then suddenly, it stopped.

Izuku slumped forward, pressing his weight into Katsuki, pinning him to the bed.

Katsuki froze, chest heaving, pulse hammering like it might crack his ribs.

Something wet hit the hollow of his throat.

Tears.

Izuku was… crying?

Katsuki’s entire body went still.

“Izuku…?” he asked, voice tentative. His hands hovered near Izuku’s back, fingers flexing and curling in hesitation. He didn’t know what the hell he was supposed to do. None of this was in his playbook.

Izuku’s shoulders kept trembling. The faint, broken hiccups under his breath turned louder, gathering force until they spilled out in sharp gasps.

“Why- why can’t I stop this? Why?” 

The words tore out of him in a hoarse, uneven whisper, barely more than breath. He wasn’t speaking to Katsuki. Not really. 

“Why am I always so… so selfish?” he said, twisting handfuls of the sheets. “I have so much. I’ve been given so much. I love teaching. All Might’s alive. Kacchan’s always there for me. But- but I still feel so pathetic. I still want more. I constantly think about things I shouldn’t. I want things I shouldn’t. And now… now One For All-”

His voice cracked, unraveling completely.

“It’s gone. It’s all gone. Gone. Forever.”

A bell went off in Katsuki’s mind. Izuku’s twentieth birthday. 

Katsuki had met him after his shift at UA, casually offering to meet up, maybe see if any of their old classmates wanted to grab dinner, have a drink or two.

Izuku had smiled.

That smile.

That specific fucking smile Katsuki knew far too well. The one he’d seen too many times to count; polite and sheepish on the surface, touched with awkward charm, but always, always masking something heavier. Something unresolved and buried so deep it only slipped through the cracks when Izuku let his guard drop, which was rare. Especially around others. 

He’d told Katsuki he had something else to take care of. Something more important than a birthday drink, more urgent. And Katsuki, against his better judgment, had let it go.

Had this been what he meant? Had Izuku gone drinking alone, spiraling quietly in the dark, slipping somewhere between grief and longing and winding up in Katsuki’s old dorm room, chasing the shape of something he couldn’t hold anymore?

“The last ember…” Izuku mumbled, his face still buried against Katsuki’s neck. “It’s gone. I had to let it go. On my birthday. What a present, huh?”

Katsuki felt the breath catch in his chest. There was nothing he could say, not yet, because his mind was already spiraling, dragged under by memories that had never faded, not even a little.

The hospital.

The sterile light overhead, the slow, uneven drag of his footsteps down the corridor. His legs barely holding him up. Bandages pulled too tight across skin that stung with every movement. His parents hovering behind him, panicked and frantic and trying to make him stop; trying to keep him from pushing himself even further when he was already falling apart.

He hadn’t listened.

He’d forced himself forward, forced his way into the room just as All Might and Izuku were speaking. Their voices quiet, serious, laced with something final. Katsuki had barely caught the words.

The loss of One For All.

The floor had disintegrated beneath him. He remembered storming into the room, convinced he’d heard wrong. Blamed the meds. Blamed anything but reality.

But then he’d asked again. Demanded it.

And Izuku had smiled.

That smile.

God, that fucking smile. He’d tried to make it look like it didn’t hurt, like giving up the quirk he loved so much hadn’t burned a hole straight through his heart. Maybe he could have fooled the others. But not Katsuki. Never Katsuki.

Because Katsuki had felt that pain echo in his own chest. 

Katsuki couldn’t help the tears that had come, spilling down his cheeks in front of everyone: his parents, All Might, Izuku.

He hadn’t cared.

Because in that moment, all he could think was he’s going to be quirkless again. It felt like the end of something sacred.

Like losing him.

He’d grown attached to the idea - no, the certainty - that they would chase each other forever. That they’d turn pro side by side, rise through the ranks shoulder to shoulder, pushing each other to be better for the rest of their lives.

But that dream seemed to shatter the moment Izuku let One For All go.

And now, Katsuki’s breath hitched. Tears welled up again, creeping to the corners of his eyes and sliding down his temples. 

Katsuki retracted the gauntlets, letting the nanoparticles dissolve soundlessly back into the slots on his forearms, and raised a hand, his fingers threading gently into Izuku’s hair. He cradled the back of his head, grounding them both in the silence that followed.

Izuku didn’t lift his face. He stayed where he was, curled in tight and trembling, the words barely forming on his breath. “I wish I didn’t have to give it away,” he said. “I know I had to. I know. But it still hurts. I feel so alone. I miss it. I miss all of it.”

“You don’t need a quirk to be a hero, you know that, right?” Katsuki murmured, the words escaping before he could stop them. 

He wanted to add more, to explain how he’d watched what came after. How even without One For All, Izuku was still standing among them, wearing a new suit commissioned by friends who refused to let him vanish from the frontlines. How he still inspired them. How he still saved people.

Katsuki didn’t even know if this moment was real. He didn’t know if time had twisted or broken, if this was memory, hallucination, dream, or whatever the fuck. But that didn’t matter.

Because it was still Izuku. 

That much, he felt in his bones. And for that, for him, Katsuki would have torn apart the world to make things right. To give him back even a sliver of what he thought he lost. To see him smile and believe in it, for once, without pain sitting just beneath the surface.

Izuku let out a soft, bitter snort; half laugh, half sob. His shoulders trembled beneath Katsuki’s hands.

“Of course you’d say that,” he said, words coming out wet and trembling. “You’re my dream.”

Katsuki’s breath caught, stuck somewhere between surprise, frustration and disbelief. “For god’s sake, what makes you so fuckin’ sure I am?”

Izuku pushed himself up from Katsuki’s chest, fingers grazing skin like he wasn’t sure if he wanted to connect or pull away. He blinked down at him, eyes glassy, still wet from unshed tears. “Why these questions again? Why are you like this today?” His voice cracked slightly before he added, “Kacchan… he would never allow me to- well-”

Katsuki raised an eyebrow, his smirk half a grin, half a challenge. “To fuck him?”

Izuku’s eyes went wide. “W-well, y-yeah!”

Katsuki snorted low, amused. “What’s this? Suddenly lost all your guts?”

“I- I just-” Izuku stammered, clearly shaken, his face glowing with embarrassment.

Katsuki leaned in slightly, voice dropping low. If Izuku really believed this was all a dream, then maybe he would speak honestly. Maybe now was the moment Katsuki could find some truth in the chaos. Risky as hell, but what did he have to lose?

“You ever even tried with him, you damn nerd?”

Izuku recoiled, his face aflame with shock and disbelief. “What?! No! Of course not!!”

“Why the fuck not?” Katsuki snapped.

Izuku flinched like the question had been a slap. “Are you serious right now?” he asked, incredulous. “You think I could just- just do something like that?”

“Why the hell not?” Katsuki repeated, quieter now. He moved closer, nose almost brushing Izuku’s. “Answer me, Izuku.”

Izuku held his gaze for a moment, something wavering behind his eyes. Then he pulled away, carefully.

He slipped out of Katsuki’s arms and sat at the edge of the bed, elbows on his knees, head bowed. His curls fell forward, hiding his face.

“Why am I doing this?” he whispered, more to himself than anything. His voice was breaking at the edges again.

“Yeah, why?” Katsuki echoed, moving to sit beside him. “That’s what I’m asking, you fucking dumbass.”

“I-I’m… so pathetic,” Izuku said, barely audible.

Katsuki’s jaw flexed. He drew in a sharp breath through his nose. “Can you just stop saying that already?”

“It’s the truth!!” Izuku shot back, lifting his head at last, eyes red and blazing. “I’m sitting here in Kacchan’s old bedroom, imagining doing all these things to him! Not just now. Not just because I feel bad about One For All.” His voice wavered under the strain of holding back tears. “I do this all the time, it’s driving me insane. It’s an obsession. It’s been years - years - and I can’t stop. I keep seeing things in my head that I shouldn’t. Wanting things I don’t deserve. I should be ashamed. Anyone in their right mind would be.”

He buried his face in both hands, shoulders trembling. “He’d hate me if he knew. He’d just hate me.”

Katsuki just stared, air trapped in his lungs. 

So it wasn’t some passing thought. Izuku had these fantasies… constantly.

And Katsuki had never had a single clue. And did Izuku seriously think he’d hate him for it? 

Katsuki’s chest twisted around that truth.

He swallowed hard. 

“You fuckin’ stupid nerd,” Katsuki hissed. “You think beating your own ass down is gonna fix anything?”

Izuku flinched, but said nothing, shaking in place, hair brushing over his forehead.

Katsuki leaned in, words tearing free before he could stop them. “Go talk to him, for fuck’s sake! Just… go ask!”

“No!” Izuku’s hands fell away from his face. He shook his head violently, curls flying around his temples. “No, no, no, no!”

Katsuki grabbed a fistful of Izuku’s shirt, yanking it just enough to force him to look up.  “What’s your damn problem, Izuku??”

Izuku’s chest rose and fell rapidly, mouth barely parting. His eyes glistened with unshed tears. “Stop, stop!” he whispered, voice cracking. “I just- I just need to put myself together.”

Katsuki just stared, his hand still clutching Izuku’s collar, holding him steady. This dumbass wasn’t willing to say what was really on his mind, not even here, where he thought it was all a dream. It was so fucking infuriating.

Katsuki had no clue when the damn light would flicker back on. No idea how much time he had left. No clue if this Izuku would remember any of this… or if it’d mean anything at all.

He didn’t know shit anymore.

So he asked, against every better instinct. 

“Is it only me?”

Izuku blinked, confused. “What?”

Heat crawled up under Katsuki’s skin, shame curling behind his ears and prickling the back of his neck.

“You dream about me,” he said, voice trembling as he fought to keep it steady. “You- you think about me. Like that.” He swallowed hard, jaw twitching. “But… is it just me? Isn’t there anyone else?”

Izuku stared at him like Katsuki had suddenly started speaking a language he didn’t understand. “What do you mean? Who else would there be?”

“I- I don’t know. Fuck.” Katsuki looked away, flustered. “R-round cheeks, or- or whoever the hell else.”

“Uraraka?!” Izuku squeaked. The blood drained from his face in an instant, only to rush back so violently that his cheeks flamed a deep red, so fast Katsuki thought he might pass out.

There it was.

Fuck.

That was it. Izuku had thought about her too. Of course he had. Of course. 

At least now Katsuki knew.

He let go of Izuku’s collar and sank back, a hollow weight dropping into his chest.

But before he could say a word-

“Are you serious?” Izuku asked, still flushed and visibly shaken.

“I asked, didn’t I? Of course I’m serious,” Katsuki snapped inwardly, already regretting how deep he’d let himself get into this mess.

“Oh my god… God no!!” Izuku burst out, eyes wide with disbelief. “Of course not! Why would I fantasize about her?!”

He looked flustered beyond reason, utterly mortified.

Katsuki blinked, thrown completely off course.

“You-” he started, throat suddenly dry. “You’ve always seemed… close.”

“She’s my friend, yes!” Izuku shot back, exasperated. “I-It doesn’t mean that I- Oh my god!”

He buried his face in both hands. And Katsuki could only stand there, watching.

He swallowed hard. Words failed him.

Sure, it was a relief… knowing Izuku didn’t think about Uraraka like that. But then again, what the hell did that even prove? What if this wasn’t real? What if it was just his own head making shit up, feeding him exactly what he wanted to hear? A trick. A lie. Something soft and sweet to keep him from falling apart completely.

Shit.

“It’s you and no one else, Kacchan,” Izuku said at last, voice worn thin. He stood slowly, gaze fixed somewhere near the floor. “It’s always been like that. But I have to end this. It’s not normal. I need to stop believing you belong to me. It’s all in my head. It’ll never happen. And… thinking it could be real… Why do I keep doing this to myself? I’m only making it worse.”

“Izuku-” Katsuki stepped forward, hand reaching instinctively toward him, but froze mid-motion. Didn’t touch him. Let it fall.

“Let me go,” Izuku said quietly. “I must’ve had more to drink than I thought.”

Katsuki didn’t know what the hell to do. Some part of him wanted to shake that stupid nerd until he understood; until he realized this was real, that he was real. But was he? Was any of this?

Fuck. He was losing it.

“Goodbye, Kacchan,” Izuku said.

And there it was. That motherfucking smile.

Katsuki would’ve burned the whole world to never see it again.

But before he could speak, before he could even move-

Izuku was gone.

The door clicked shut behind him.

Katsuki stared at it, jaw tight, fists clenched.

His chest ached. He was pissed off. He was helpless. And, somehow, still fucking turned on.

Shit.

His mind was still reeling when it happened again.

That goddamn light.

The shift.

The pull.

Back into whatever the hell this was.

How many times now?

Would it ever stop?

And what the fuck was he supposed to do to make it end?

What was the point of any of this?

And suddenly, he was in another goddamn room.

A living room this time. Not too big, not too small. He flicked on the light for a better look.

He knew this place.

He’d been here before. Maybe not often, but enough to recognize the details; the kind that’d give this place away at a glance.

Teaching manuals and hero history books stacked neatly by the coffee table. Hero merch crammed into corners, some of it probably decades old. A whole damn army of All Might figures standing guard on the shelves like they owned the place.

And pictures. So many pictures.

That nerd had gotten into photography back at UA, and he never dropped the habit. Every outing, every mission, every breath that seemed remotely worth remembering; he took the shot.

And damn it, Katsuki couldn’t lie.

He was good.

Really fucking good.

Those photos never felt staged, even when they were. Somehow, Izuku always managed to catch the parts the rest of them missed. 

Even when it was Katsuki. Hell, especially when it was Katsuki: caught doing something stupid, like frowning too hard at his phone trying to pick a restaurant for him, Todoroki, and Izuku. A second no one else would’ve thought twice about, and yet there it was, framed like it meant something.

Now that he thought about it, that particular photo was recent; just last winter. Which meant… was he in the present now?

Logically, it could only be Izuku’s current birthday.

Katsuki was still half-lost in that thought when he heard the front door open.

Footsteps. A solid thud as shoes hit the genkan.

And a voice. The one voice he knew better than any other, rising and falling with a sharp edge of worry as it came closer.

“Are you sure?” Izuku was saying, tone taut, urgent. “I need you to reassure me that nothing bad happened to him!”

Katsuki stared at the entrance to the living room, pulse rattling in his throat as Izuku’s silhouette appeared in the doorway.

“I should meet him soon? I swear to god, if he’s hurt… if he’s hurt, someone else is getting hurt too,” Izuku snapped, words tumbling out fast.

He was dressed exactly as Katsuki had left him earlier at the party: crisp white shirt, dark green slacks that should’ve been illegal on those legs. He still hadn’t noticed Katsuki standing dead center in the room, too wrapped up in his call.

“You already know too well? What do you mean, Monoma?”

Monoma.

Him again? 

Before Katsuki could string the pieces together, Izuku’s eyes lifted… and landed on him.

Phone still in his hand, Monoma’s voice buzzing on the other side.

But none of it mattered, because all of Izuku’s focus had snapped to him.

“Kacchan,” he breathed, eyes wide, color draining and flooding back into his face all at once. “I was so worried! You… you just disappeared! Where were you?”

Katsuki didn’t answer. He just closed the space between them.

He stopped right in front of Izuku, who watched him in stunned silence, fingers still clutching his phone. Without a word, Katsuki reached out and plucked it from his grip.

“I’ll deal with you later, bastard,” he snarled into the receiver, then ended the call and tossed the phone onto the couch without looking where it landed.

All that mattered now was Izuku.

Izuku, standing there, staring at him like he’d just been struck by lightning. 

And Katsuki didn’t have the answers. Not yet.

He didn’t know if this was truly real; if that last shift had finally dropped him back into the present. Or if the warped versions of Izuku he’d seen in those time jumps, the ones so hungry, so desperate, eyes dark with obsession, weren’t hallucinations or fragments of some fevered dream.

But if they were real, if any piece of it was true… then this was his chance.

And he wasn’t going to waste it.

He closed the distance deliberately, though inside he felt like chaos was tearing through him. His gloved hands rose to cup Izuku’s face, the cool leather a sharp contrast to warm skin. He could feel the faint tremor in Izuku’s jaw, the breath caught in his throat.

Then he kissed him.

And, sure, it felt real.

The heat of Izuku’s lips, the soft, startled sound he made, the way he instinctively leaned forward even as his hands hovered in the air, unsure where to land.

When Katsuki pulled away, Izuku’s cheeks burned bright, eyes wide with shock.

“W-what was that?” Izuku stammered, bewildered.

“The fuck do you think it was, dumbass?” Katsuki shot back. Shit, his heart was pounding so hard he thought it might burst. 

How the hell could Izuku always be this stupid?

Izuku blinked, confusion melting into worry. His eyes scanned Katsuki’s face.

“Kacchan… you okay? Did someone hurt you? Did a villain hit you with a quirk?”

Katsuki let out a harsh breath and slapped a hand over his own cheek. God, Izuku was such a goddamn infuriating nerd.

Even though, in the end, his question wasn’t exactly wrong.

“Shit. How do I fuckin’ explain this-” Katsuki began, a faint flush still creeping across his cheeks.

Technically, something had happened. A quirk had hit him. He was about to spit out the whole story, this twisted back-and-forth reality he’d been stuck in, until he noticed Izuku’s eyes drop.

Izuku’s stare went glassy, his mouth opening as if to speak, but nothing came out for a few seconds.

“W-what’s that?” he finally managed, voice hushed.

Katsuki followed his gaze… and felt heat spike through his body.

Oh.

Fuck.

His top was still unzipped halfway, baring his throat and the upper part of his chest. Whatever mark past-Izuku had left there must have been impossible to miss.

Izuku’s face flared so red it was almost purple.

“Who… who did that?” he whispered, like the question slipped out before he could stop it.

Katsuki met his eyes squarely.

“You,” he said, simply.

Izuku froze. “Huh?”

“Yes, you, you stupid, perverted nerd.” Katsuki insisted, a little smirk forming on his face.

“B-but-” Izuku sputtered, eyes wide, voice nearly cracking. “How? Please stop… stop messing around, Kacchan!”

“I’m not messing around.” Katsuki leaned closer. His gloved fingers hovered near Izuku’s arm, not quite touching. “It was you. In my old UA dorm room. How much did you love sneaking in there, fantasizing about fucking me senseless, you freak?”

Izuku made a choked noise. 

“How d’you even know-” he blurted out, slapping a hand over his mouth, as though realizing too late he’d given himself away.

Katsuki tilted his head, teeth flashing in a grin.

“And those ‘Personal notes for research purposes only’,” he said, nodding toward his own groin. “Still curious to see if you were right?”

Izuku stood completely still. His breath came fast. A sheen of sweat glimmered at his temples.

Katsuki watched him for a long moment, almost laughing at the sight. 

So it was true, right? Not a twisted trick his mind played, or another effect of that damn quirk. Everything was too vivid, too real. And this Izuku… he was unmistakably his Izuku.

As ridiculous as it sounded, Izuku really did have those damn notes, scribbling down every awkward guess and measurement, obsessing over the shape and size of his dick. He’d actually sneaked into that old UA dorm, driven by the filthiest thoughts imaginable.

Heat prickled beneath Katsuki’s skin despite the cocky tone he’d just thrown out.

He was about to tease a little more, try to push him to the edge, when Izuku’s broken voice cut through the tension.

“Are you… a dream?” Izuku whispered. “Am I dreaming again?”

Katsuki blinked, caught off guard. His grin slipped away, lips parting in silence.

“It’s been… a while since I had a dream that vivid,” Izuku said. “I tried to forget. Tried to shove those fantasies down after that night. After losing the last ember of One For All. Why now? Why again?”

And suddenly, everything clicked into place.

The quirk had dragged Katsuki back in time, and it had messed with Izuku’s perception. He’d actually lived through those moments but thought they were only dreams. Maybe that was the quirk’s nature: making those memories feel like hallucinations.

And for Izuku, someone who already tended to lose himself in his own fantasies, it must have worked flawlessly.

“Izuku.” Katsuki grabbed his shoulders. “I’m here. I’m real. And I’ve probably been real even in some of what you thought were dreams.”

Izuku blinked, puzzled. “What do you mean?”

“I’ve been hit by a quirk,” Katsuki said. “Motherfuckin’ Monoma sent me to the past. And I met you. Past versions of you. On some of your birthdays.”

Izuku’s eyes widened. “W-wait. So- you’re telling me that-”

“Yeah,” Katsuki cut in. “Sometimes you saw me. In person.”

He leaned closer, lips brushing against Izuku’s when he spoke.

“Your hard cock pressing into my thigh when you fell on me in the street? Such a damn freak, even as a baby.”

Izuku swallowed hard, face blazing red.

“And all those sketches of my dick?” Katsuki went on, voice low. “Who’d have guessed you were so damn devoted to studying it, you perverted nerd?”

“It- it was just- resear-”

“And what about you grinding on me in my old room?” Katsuki said, breath washing over Izuku’s parted lips, which were trembling now. He felt his own pulse pounding so hard it hurt. 

Fuck it. He wasn’t holding back anymore. 

Now or never.

“For you, it might’ve been years ago. For me, it was just minutes ago.”

Katsuki brushed his gloved thumbs lightly across Izuku’s cheeks, feeling heat radiating from his skin.

“Now I’m so fucking angry.”

“Wait, Kacchan, I didn’t- I-”

“‘Cause I’m so fucking horny.”

Before Izuku could get out another word, Katsuki surged forward and pressed his hard length against Izuku’s groin. The contact tore a gasp from Izuku’s throat.

“How about you finish what you started in my old room?” Katsuki murmured against the shell of Izuku’s ear. His hand dropped to Izuku’s waist, gripping tight enough to make him jolt. 

He leaned back just far enough to see Izuku’s face, bracing for hesitation, embarrassment, resistance… anything. But Izuku just stared at him, face completely flushed, breath shaking.

Then all thought vanished.

One second, Izuku’s lips were parted, struggling for air. The next, he crashed forward, kissing Katsuki so hard their teeth clacked.

It was hot and messy, tongues tangling, Izuku’s body pressing in like he couldn’t get close enough. Katsuki tasted beer on his lips, salt on his tongue, and it made him even hungrier. Fuck. Katsuki barely managed a breath before Izuku’s tongue slid deeper, desperate, like he was trying to crawl inside him. 

A low groan ripped out of Katsuki’s chest. He kissed back harder, teeth scraping Izuku’s bottom lip, one hand fisting in the wild curls of Izuku’s hair, the other gripping his side. He yanked Izuku flush against him, tilting his head to deepen the kiss until their mouths were slick and gasping.

Izuku broke away with a sharp inhale, his breath shaky. Then he rolled his hips forward, grinding down hard against Katsuki’s cock. Sparks shot through Katsuki’s body so sharply he nearly whined out loud.

“Fuck-” Katsuki hissed, dragging his mouth away just enough to suck in ragged air. “If only I knew you were so eager.”

Izuku didn’t even seem to hear him. His eyes were wild, pupils blown so wide there was barely any green left.

Then he growled, and shoved Katsuki backward. Katsuki stumbled, knees buckling against the sofa behind him, dropping onto the cushions.

Before he could blink, Izuku followed.

He climbed into Katsuki’s lap, straddling him, thighs spread wide. The weight of him landed heavy and perfect over Katsuki’s cock, making him bite back a moan.

Heat radiated off Izuku like fire. He grabbed the front of Katsuki’s costume and yanked him forward, kissing him again, lips devouring every sound Katsuki made.

Katsuki groaned into his mouth, pushing his hips up instinctively, chasing that friction. His fingers slid down Izuku’s sides, pressing into the grooves of muscle beneath the thin fabric. He wanted to tear it off. Wanted to see every bit of skin, bite every spot that made Izuku gasp.

Izuku broke the kiss with a rough breath. His eyes were glazed, lips swollen and shining with spit.

“I don’t want you to vanish, Kacchan,” he panted. “Don’t leave me. Don’t leave me this time.”

“I won’t,” Katsuki growled, voice husky, breath hot between them. “I’m here, Izuku. I’m not going anywhere.”

He yanked Izuku closer, crushing their mouths together so hard their teeth knocked. Izuku moaned, hips rolling in slow, hungry circles. Every shift sent shots of heat spearing through Katsuki’s veins.

Izuku clung to his shoulders, pressing wet kisses along Katsuki’s jaw. Lips and tongue traced a path lower, dragging heat in their wake.

He found the hickey his past self left on Katsuki’s neck, and bit down hard.

“Shit- Aaah!” Katsuki choked out, hips jolting despite himself. The sting ignited a wildfire beneath his skin. He’d have let Izuku drain him dry if he asked. Fuck.

His hands dropped lower, seizing handfuls of Izuku’s ass and hauling him closer. Izuku shivered at the rough grip, hips lurching forward, grinding harder against Katsuki’s swollen cock.

Izuku drew back just enough to whisper, “Say it again. I need you to say that again.”

Katsuki blinked, his thoughts scattered. “Say what?”

“That you’re not leaving.”

“I just came back,” Katsuki snarled, voice ragged. “I’m not fuckin’ leaving.”

He lunged forward, sealing their mouths together in another kiss.

When they finally broke apart, Katsuki paused, holding Izuku steady, eyes roaming over him. Izuku looked wrecked. Cheeks burning, damp hair clinging to his forehead, eyelids heavy, pupils blown wide with hunger. He was perfect.

Katsuki tore off his gloves, then reached up, sliding his bare fingers along Izuku’s flushed cheek, savoring the feel of warm skin against his own.

“So,” Katsuki rasped, smirking. “How much have you obsessed over my dick, you perv?”

Izuku barely even blinked. “You don’t wanna know.”

“Oh, I fuckin’ do.” Katsuki caught Izuku’s wrist, guiding it down and pressing it firmly against the shape of his bulge. “Guess it’s time to see if you were-”

He didn’t even get the words out. Izuku’s hand was already gripping him through the fabric, squeezing and rubbing along the length of him, making Katsuki’s breath catch in his chest.

It didn’t take Izuku long to undo Katsuki’s belt, pop the button on his pants and yank the zipper down. Katsuki sucked in air through clenched teeth as Izuku cupped him over the thin barrier of his underwear. His cock jerked beneath Izuku’s touch, straining for more.

“I had my theories,” Izuku murmured, as he peeled away the last layer of fabric.

He stared down at Katsuki’s freed cock, eyes dark, an unreadable expression flickering across his face. It made Katsuki suddenly, irrationally self-conscious.

“And I wasn’t wrong.”

Izuku’s scarred fingers curled around him, stroking slow and deliberate from base to tip. Katsuki’s hips rocked forward, searching for every bit of friction Izuku would give.

Izuku looked absolutely mesmerized by him; by the way his cock twitched under each stroke, how precum gathered and glistened along the ruddy skin, gliding beneath Izuku’s sliding fingertips.

“So big,” Izuku breathed, voice reverent. “Even better than my imagination.”

He shifted, sliding off Katsuki’s lap and sinking to his knees on the floor. His face hovered level with Katsuki’s cock, his eyes flicking up, hungry and soft all at once.

“You’re so amazing. You’ve always been amazing.”

Izuku leaned forward and pressed soft, lingering kisses along the underside of Katsuki’s shaft, still stroking him with one hand. Katsuki let out a strangled groan, his thighs tensing.

Then Izuku’s tongue snuck out, tracing a prominent vein, flicking over the sensitive ridge of his tip, licking up the slick gathering there. A coil of fire settled low in Katsuki’s belly, breath shallow as Izuku mapped every bit of his dick with his mouth.

Katsuki dropped his head back, a guttural sound tearing out of his throat. He wasn’t sure how much longer he’d last at the rate Izuku was going, but right now, he couldn’t bring himself to care.

Just as Katsuki braced for Izuku to take him fully into his mouth, Izuku pulled back, lips shining, tongue darting out to swipe the lingering taste. His eyes locked with Katsuki’s.

“I want you, Kacchan,” Izuku murmured, voice so low and sultry that its sound alone sent another sharp twitch through Katsuki’s cock. “I want you right now.”

“Then don’t waste any fuckin’ time,” Katsuki shot back, words filled with lust.

Izuku scrambled to his feet, vanishing into the other room and reappearing seconds later with a bottle of lube clutched in his hand. He paused, cheeks flushed, looking suddenly flustered.

“I- I don’t have any condoms,” he blurted, like confessing a secret sin.

“So?” Katsuki’s mouth curled into a wicked grin. He was actually relieved Izuku didn’t have any on hand; a sign the nerd wasn’t out there screwing around.

“I just… I don’t know if you-” Izuku started, but Katsuki cut him off before he could finish. This wasn’t the moment for cautious conversations.

“You clean?” Katsuki snapped.

“Well- yes, yes, I am!!”

“Then we don’t need a damn condom,” Katsuki growled.

“What about y-”

“For fuck’s sake,” Katsuki shifted onto the sofa, bracing himself on hands and knees, ass high, presenting himself completely. “Cut the bullshit and fuck me now.”

He had no idea how he managed to sound so confident. Nobody had ever fucked him before. All he’d known were fantasies and his own fingers, and he never truly cared about sex-

Unless it was Izuku.

Now the only thing he wanted was to feel Izuku inside him, driving him wild, fucking him until he forgot everything but his name on Izuku’s tongue.

And Izuku didn’t hesitate a second longer.

Rough hands tugged Katsuki’s pants and underwear down, leaving him exposed. Fingers roamed over the curve of his ass, tracing lines of heat along his skin.

“So gorgeous,” Izuku murmured, his words dripping with hunger.

Katsuki craned his neck just enough to glance over his shoulder. The sheer, unfiltered want blazing in Izuku’s eyes made his own cock twitch so hard it almost hurt.

Izuku snapped open the lube and squeezed a generous amount onto his fingers. The sudden chill against Katsuki’s heated skin ripped a violent shiver from him.

But it wasn’t just the cold that had him shaking; it was a wildfire of anticipation crackling beneath his skin. He needed Izuku’s fingers inside him, prying him open, dragging every filthy, wrecked sound from his throat.

Izuku’s own hands were trembling slightly, but that didn’t stop him from leaning closer, determination etched into every line of his face. He pressed the tip of a finger inside, cautiously at first, testing the give of tight muscle.

“You feel so real, Kacchan,” Izuku rasped, words coming out raw and unsteady as he pushed deeper. “So hot. So incredible.”

“Y-you still… think I’m… some kinda halluc- aaaah, fuck!” Katsuki choked out, his entire body shaking as heat shot through him.

“No.” Izuku’s answer was a rough growl, as he slid in a second finger. Katsuki cried out, the stretch sharper than before, igniting sparks along his spine. “But it still doesn’t seem real. It’s absurd. I can’t believe you’re letting me do this… letting me touch you like this.”

“You better believe it,” Katsuki snarled, grinding his hips backward, desperate for more pressure, more friction. “And you better fuck me like you mean it, you goddamn nerd.”

Izuku pushed in a third finger with barely any warning, forcing Katsuki’s body to yield around him. Katsuki’s mouth fell open in a silent shout before he finally managed to gasp out a strained, “Shit-!”

Izuku’s breathing turned savage, each exhale rough and uneven as he worked Katsuki open, stretching him wide. His free hand clamped down on Katsuki’s shoulder, fingers digging in possessively. The sheer strength in that single grip sent Katsuki’s thoughts spiraling; imagining all the filthy, ruthless things Izuku could do to him with those hands alone.

A sudden, guttural moan tore out of him when Izuku’s fingers brushed over a spot inside him that sent electric shocks bursting through every nerve.

“F-fuck… aaah… shit-!” Katsuki babbled, his voice cracking under the weight of the pleasure.

“D’you like this, Kacchan?” Izuku asked. When Katsuki turned his head again, he saw a cocky, wicked smirk playing over Izuku’s lips.

“Wh-what the hell… d’you think…?” Katsuki barked, trying to muster a glare, but the tremor in his voice broke through the bravado.

“You better say it out loud, Kacchan,” Izuku demanded, fingers ruthlessly pressing into that same perfect spot. Katsuki let out a strangled whimper, bucking back against the relentless touch. 

“Y-yes,” Katsuki gasped out, eyes screwed shut as pleasure coiled tight and hot in his belly. “Fuck, yes!!”

Izuku exhaled a shuddering breath, pupils blown wide as he slowly withdrew his fingers, leaving Katsuki feeling raw and empty.

“Now I can finally fuck you,” Izuku rasped. He paused a moment, just enough to let his gaze roam slowly over Katsuki’s quivering body, as if he needed to memorize how he looked in this moment. “Are you sure you want it, Kacchan? From me?”

“Seems the time to backtrack now?” Katsuki panted, chest heaving, the damp fabric of his costume clinging to every curve of hard muscle. “Fuck me so hard you forget how to fuckin’ breathe.”

A strangled groan tore from Izuku as he unbuckled his belt in a frenzy, the metallic clink echoing in the heated silence. He yanked down his zipper and shoved his slacks and underwear down, his cock springing free, thick and flushed and leaking at the tip.

Katsuki’s eyes flew wide, heat spiking all over his skin, his own dick giving an eager jerk at the sight.

“Y-you nerd-” Katsuki sputtered, unable to tear his gaze away as Izuku slicked his shaft with lube, every glide of his hand sending lewd, wet sounds into the room. “Who the hell knew you could grow something that… fuckin’ big?”

Izuku leaned closer, his breath hot against Katsuki’s ear, voice dropping to a molten whisper. “Wanna feel it, Kacchan?”

“Y-yes,” Katsuki growled, fingers digging into the cushions like claws. “Fill me up. Give me all of it.”

Izuku spread Katsuki’s cheeks and eased closer, the head of his cock nudging against Katsuki’s rim. A sharp gasp burst from Katsuki when the blunt tip breached him, heat flooding through his core.

When Izuku pushed in just the tip, Katsuki couldn’t stop the broken squeal that escaped from his throat.

“I-it’s… so fucking big,” he panted, gripping the cushions until his knuckles whitened.

“Are you okay, Kacchan?” Izuku asked, breathless, a note of worry threading through the lust in his voice.

“Yes.” Katsuki shot back, almost snarling the word. The stretch was new, sharp, overwhelming; but there was no way in hell he wanted to stop. Not now they finally got there. “Don’t you- don’t you dare fuckin’ hold back on me!”

A shudder rippled through Izuku. Then he pushed forward, burying himself in one thrust until his hips pressed flush against Katsuki’s ass.

“So… so tight,” Izuku gasped, the muscles in his arms straining as he fought to stay still for a heartbeat.

Katsuki let out a feral growl, shoulders trembling as he rocked his hips back, craving for more. “Move, nerd. The fuck are you waiting for?”

Izuku’s restraint shattered in an instant. 

His first thrusts were careful, testing how Katsuki’s body took him, but the rhythm grew fast. His hands locked around Katsuki’s waist, thumbs pressing into bone so hard that Katsuki was certain they’d bruise him.

“You’re real,” Izuku rasped, as if still fighting to believe he wasn’t caught in another of his fantasies. “You’re here. You’re real.”

Katsuki tried to answer, but words died under the onslaught of pleasure. His mind was hazy, wrecked by the relentless pace, his cock leaking thick drops onto the pale leather beneath him, the smear growing with every ragged buck of Izuku’s hips.

Only guttural noises spilled from Katsuki’s lips; grunts, gasps, choked moans, his entire body alive under Izuku’s touch.

Tears welled and slipped free, streaking his flushed cheeks as Izuku kept pounding into him. Izuku’s hands slid beneath Katsuki’s costume, nails scraping over wet skin. Droplets of sweat fell from Izuku’s face, dotting Katsuki’s spine.

“You’re mine,” Izuku growled, voice darkening, his grip tightening. “You’re only mine.”

Katsuki wanted to say I am, wanted to say it so badly, but all that escaped was a broken gasp, caught between trembling breaths, his chest heaving, the heat inside him rising to something close to unbearable. He turned his head just enough to catch a glimpse of Izuku.

And it almost undid him completely.

He looked so fucking gorgeous. His hair, damp and clinging to his forehead, framed eyes gone nearly black with hunger. His white shirt, soaked through with sweat, clung to every cut of muscle, the fabric molding to the shapes of his chest, the hard points of his nipples visible beneath the thin cotton. His lips were parted, face flushed, as he kept thrusting.

“I don’t want anyone else… to have you,” Izuku said, eyes glittering, his pupils swallowing the green around them. He fisted Katsuki’s hair and tugged, the sharp pain exploding along Katsuki’s scalp, jolting another wrecked moan from his chest. 

“Nobody else. Ever. You’re mine. Only mine.”

“I’m- aaaaah!”

“I’m only yours, forever.”

The words wouldn’t form. Everything was too overwhelming; Izuku was stripping away everything: Katsuki’s will, his mind, his senses, until all that was left was the desperate need to belong. 

To him. Only to him.

Whatever fragile control Izuku had left suddenly snapped. He pulled Katsuki’s hair even harder, forcing his spine into a deep arch. His other hand clawed at Katsuki’s waist, fingers digging into muscle so fiercely that a sting of pain flared under the steady grip. Katsuki felt his skin burning where Izuku’s nails scraped him open, blood mixing with the sweat streaking down his sides.

But he didn’t care. The pain only fused with pleasure, turning the throbbing heat inside him into something feral.

Fuck, he was so close now.

“Iz- Izu-” he tried, words broken, his voice a thin thread as he trembled. “I’m- clos- aaahh!”

Izuku didn’t seem to hear him. He thrusted into Katsuki without flinching, hips snapping forward again and again. Every hit punched a sharp cry from Katsuki’s chest, sent his cock leaking even more onto the sofa beneath him.

“I’m gonn-” Katsuki choked, eyes squeezing shut as stars danced behind his eyelids, his entire body tightening around Izuku’s thick length. “I’m-gonna… make a- mess-”

“Come,” Izuku rasped, his voice deeper than Katsuki had ever heard it. “Come for me, Kacchan. Let me see you. Let me hear you scream.”

And that was all it took.

Katsuki’s hand flew to his aching cock, fingers wrapping around the shaft slick with sweat and precum. His grip tightened as he stroked himself in a desperate rhythm, every nerve ending alight, his vision turning white around the edges.

He let out a sound that was half scream, half sob, as his orgasm crashed through him. His cock jerked violently in his fist, ropes of cum spilling over his knuckles and dripping down onto the pale leather of the sofa. His entire body shuddered, tears streaming down unstoppably, muscles locking tight, his hole clenching rhythmically around Izuku’s cock still buried deep inside him.

For a moment, the only sounds in the room were the slick slap of Izuku’s hips and Katsuki’s choked whimpers, the sharp scent of sweat and sex hanging thick in the air.

Izuku leaned over him, pressing hot, open-mouthed kisses along his bare shoulders, breath coming in harsh, uneven pants. 

“That’s it… so beautiful… all mine.”

The words dropped low, before he paused. A glint of sorrow glimmered at the edges of his voice.

“At least… for tonight.”

The shift in Izuku’s tone carved through the haze. Katsuki’s head fell forward, sweat dripping from the ends of his hair. His whole body trembled, nerves shot through with heat, muscles quivering from strain and pleasure. He felt exposed, stripped of every defense, utterly undone… and he couldn’t remember ever wanting anything more.

Izuku’s movements grew rougher, urgency pouring from his body as he drove into Katsuki, hips snapping forward. Katsuki felt Izuku shudder as he fucked in right to the hilt one last time. A sharp, choked cry ripped out from Izuku’s throat as he spilled inside him, warmth flooding deep, pulsing with every wave of his release: “Kacchan!”

Hearing Izuku scream his own name like that made Katsuki’s chest seize. He wanted to memorize the sound, brand it into his bones, listen to it forever.

Izuku stayed buried in him for a few trembling breaths, gasping, body still trembling from the aftershocks. Slowly, hesitantly, he pulled free, the shift making Katsuki shiver with oversensitive nerves and the sudden, stinging emptiness that followed.

Katsuki lingered, eyes falling shut for a few seconds as he tried to catch his breath. He moved with deliberate slowness as he pulled his underwear and pants back on, not ready to shatter the fragile calm hanging between them.

Izuku was already standing by the time Katsuki rose to his feet, fingers fumbling as he adjusted his slacks, his face a mask of distant focus that seemed painfully out of place after how desperately he’d just held onto him.

Before Izuku could step away, Katsuki lunged forward, hand shooting out to grab the front of his shirt. He hauled him close, crushing their mouths together in a kiss that was wet, urgent, clinging. He poured every last drop of feeling into it; the sparks of lust still crackling between them, the quiet fear of losing the warmth they’d just shared.

When they finally broke apart, Katsuki pressed his forehead against Izuku’s, fingers threading through the sweat-damp hair at the nape of his neck, anchoring them both in the heavy silence that followed.

“Thank you, Kacchan,” Izuku murmured at last, voice trembling around the syllables, the fierce fire of minutes ago dissolving into something fragile and hesitant.

He pulled back, gaze shifting sideways, and for an instant, a shadow of pain crept through his eyes.

“I’m sorry.”

Katsuki stared at him, a tight knot twisting painfully in his gut, unease and anxiety churning together.

“Sorry?” he snapped, jaw clenching so hard it ached. “Sorry… for what?”

“I… might’ve said some things,” Izuku mumbled, a flush rising on his cheeks. He kept staring at the floor as though it might swallow him up. “Please just… forget everything.”

Katsuki blinked, thrown off, then blinked again as a slow burn of rage kindled beneath his confusion.

“You can shower now,” Izuku whispered, shifting nervously. “I’ll wait-”

“Izuku.” Katsuki cut him off sharply. His hand shot up, grabbing Izuku’s face, thumb pressed just below his cheekbone. “What the fuck are you trying to say?”

“I-” Izuku faltered, trying to disentangle himself, but Katsuki’s grip held firm. “Just- just go. Please.”

Katsuki scowled, a sharp stab of panic blooming in his chest. “Have you fuckin’ lost it?”

“You don’t… have to put up with me,” Izuku murmured, eyes darting away. “I’ll just pretend this was one of my fantasies again. It’s fine.”

“No fuckin’ way.” Katsuki spat the words out, heat rising under his skin. He dropped his hand from Izuku’s face, fingers curling into fists at his sides. “No-fuckin’-way.”

“Okay… then- not a fantasy,” Izuku stammered, stumbling over his own breath. “It- it was just sex-”

“Just sex? Just sex??” Katsuki nearly yelled, fury crackling off him. He felt an urge to slam his fists into the nearest wall. “Was it just sex to you??”

“No!!” Izuku burst out, shaking his head so hard his hair whipped around his face.

“Then what?” Katsuki shot back, voice shaking with more than anger. “You think it was just sex to me??”

“I- I don’t know-”  Izuku choked on the words, breath hitching, shoulders shaking. He looked wrecked. “You said… you were horny, and-”

“And??” Katsuki snarled, stepping in closer, glare searing. “Then you ‘took advantage’ of the situation?? Is that what you’re telling yourself?”

Izuku’s mouth fell open, but no words came out.

“I can’t fuckin’ believe you.” Sparks cracked between his fingers, the urge to blast something, anything, screaming in his chest. “You seriously think I’d just do that with anyone? That I’d let someone fuck me, take advantage of me, just ‘cause I’m horny?”

Izuku was impossible. So fucking impossible. 

Always pushing, always pulling, always saying the exact thing that turned his insides inside out. Katsuki’s rage surged, tearing through his limbs. His palms glowed, heat shimmering off his skin. His arms twitched, ready to unleash the explosion screaming for release, at the floor, the furniture, the ceiling... or at Izuku himself.

But he stopped cold when he realized Izuku wasn’t looking at him anymore.

His eyes stayed low, fixed to the ground like he couldn’t stand to meet anything real. His lashes trembled. Shoulders hunched. His entire frame looked drawn too tight, too thin, stretched to a breaking point.

Then a sob escaped. Just one. And it broke everything.

Tears spilled, catching the light as they slid over his cheeks.

“This…” Izuku choked, looking so fragile that speaking seemed enough to snap him in half. “It- it means so much to me.”

He tried to breathe again, but the sound twisted, caught somewhere deep. 

“You… you have no idea how much it means to me. It’s scary.” His voice cracked, every word more fragile than the last. “It’s always been so scary.”

Katsuki didn’t move. His jaw was locked, tight enough to splinter bone. His fists still sparked, but the heat was shifting. 

He fucking hated seeing him like this.

He’d spent a lifetime hating things. Faces, places, quirks.

But this, watching Izuku crumple like that, this was different. 

Because Izuku’s pain didn’t stay locked behind green eyes or inside trembling hands. It crawled under Katsuki’s skin, wormed into the spaces between his ribs, curled up in his chest and beat in time with his own heart.

It wasn’t separate. It wasn’t something he could shove away or refuse to carry.

It belonged to him too.

And it was unbearable.

Izuku dragged in a breath that scraped, that sounded like it hurt.

“I don’t wanna ruin this, Kacchan,” he said, words tripping over his own mouth. “I- I can lose One For All. I can let go of every dream I’ve ever chased. I’ve been quirkless all my life. It’s part of who I am. Losing what All Might gave me… it hurt. It still does sometimes. But, especially now that I’ve got that incredible suit, I can… I can live with that.”

His chest heaved, caught in a frantic rhythm that left him gasping.

“But you…” His voice faltered. “You’ve always been there- all my life. I can’t even imagine what the world would look like without you in it. I wouldn’t know how to exist in that kind of world.” 

He hesitated, the words crumbling on his tongue. 

“If I lose you- If I screw this up somehow, and drive you away… then it’s not just One For All. It’s not just my dreams. It’s everything. Losing you… would mean losing everything.”

Another sob broke free, harsher this time, shaking him so hard it seemed to rattle through the room.

Katsuki surged forward, fists unclenching as he grabbed Izuku and yanked him close, crushing him in a hug so tight it stole both their breath. He wrapped his arms around him, pressing every bit of himself into Izuku until there was no space left between them. 

“And you think,” Katsuki rasped, “you think it’s not the same for me?”

He buried Izuku’s face against his shoulder, one hand braced between his shoulder blades, the other curling around the back of his head, holding him steady as if Izuku might shatter if he moved.

“You fuckin’ idiot,” he breathed, the words uneven. “You think I’d survive losing you?”

Tears slipped down his own cheeks. He didn’t wipe them away. He let them fall, because somehow it was the only thing that ever seemed to reach Izuku, to crack open those walls he always built too high, too fast.

“You think you’re the only one who’s felt like this all these years?” he whispered, voice trembling against Izuku’s hair. “You’re not. You never were.”

“Kacchan,” Izuku murmured, voice barely more than a breath, fingers twisting into the fabric of Katsuki’s costume like he was terrified to ever let go.

“I…” Katsuki pulled back just far enough to look him in the eye, though his hand never left the nape of Izuku’s neck. His thumb brushed lightly over warm skin. “I love you, you damn nerd.”

His voice cracked at the end. But there was no going back now. He was so fucking done going back, today.

“I’ve loved you so long,” he said, voice barely holding together, “I don’t even remember when it fuckin’ started. It’s just… it’s like breathing. Like it’s always been part of me.”

“Kacchan- I- ” Izuku’s voice stammered, eyes brimming and wide and impossibly bright. His cheeks were flushed, wet with tears, mouth parted.

He looked at Katsuki like he was seeing something impossible. 

“I-”

“Izuku, I swear to god,” Katsuki cut in, the words a shaky exhale more than a threat, “if you say you don’t believe me, I’m gonna blast your face so hard you won’t have a single freckle left.”

Izuku blinked at him, and for a second Katsuki felt his heart stutter in the silence. He couldn’t deal with this uncertainty anymore. Izuku was so fuckin’ stupid sometimes, Katsuki didn’t know how he’d managed all these years-

But then Izuku smiled. A soft, disbelieving laugh broke through his tears, small and bright as he scrubbed his cheeks with shaking fingers.

Katsuki could only stare.

“I… I think-” Izuku began, voice trembling. His whole face seemed to glow, even as tears clung stubbornly to his lashes. “I think I need to learn how to believe you. Not because I don’t trust you. I do, Kacchan. I trust you with my life. But… I need to learn how to love myself. I need to. I want to. Can… can you still be patient with me, Kacchan?”

“Izuku, I-”

Patient? Katsuki almost scoffed. Patient was all he’d been since the day he’d finally understood the undeniable truth: that he would sacrifice everything for Izuku. His pride, his future, even his life if that’s what it took. Waiting for Izuku to see it too, for Izuku to believe he was worth loving back, had become as natural as breathing.

Izuku swallowed hard.

“It’s just… it still feels so unreal,” he said softly. His shoulders quivered under the invisible burden he’d carried for so many years. “It’s been haunting my mind for so long. I never thought this moment would actually come. That I’d ever be… worthy of you.”

His hands lifted, trembling, to cup Katsuki’s face. His thumbs brushed away the dampness on Katsuki’s cheeks with a tenderness that nearly undid him.

“But whatever I think about myself… it doesn’t change the most important thing, Kacchan. I love you, too.”

He whispered it, and he smiled… god, he smiled. The most beautiful fucking smile Katsuki had ever seen. It was the light that had kept him fighting all these years, the reason he’d clawed his way through every nightmare, every bloody battlefield, even death itself. That smile was proof that every scar etched into his skin, every wound he’d ever taken, had been worth it. It was the one thing in this world capable of gathering all the jagged pieces of his battered heart and fitting them back together like they’d never been broken.

“I’m sure. I’ve loved you all my life… I kept it locked away like a secret too dangerous to ever let it slip free. I thought it was just a dream I’d never reach… something so close and yet always out of my grasp. I convinced myself it was enough just to stay by your side, to watch you shine from a few steps away. I never let myself believe I could wish for more. Because you’re… Kacchan. The most amazing person I’ve ever known. More than my hero. More than anything else in the world. My Kacchan.”

Izuku leaned closer, breath trembling as it mingled with Katsuki’s.

“…So, are you really sure you want to be mine?” he asked, voice small, as though he still needed reassurance even after everything.

“Of course, you damn stubborn nerd. How many times do I need to tell you?” Katsuki rasped, voice thick as tears spilled over his cheeks. “I'm here. And I'm yours. For the rest of our lives.”

Their lips met again.

This time, the kiss wasn’t rushed or harsh or desperate. It was slow, deep, reverent. It spoke all the words they didn’t have to say. It was threaded through with promises they’d spend the rest of their lives keeping, stitched together by the certainty that this, finally, was real.

When they pulled apart, they were both gasping, foreheads pressed together, eyes shining like they’d just glimpsed their entire future reflected in each other’s gaze.

“Let’s go to bed, Kacchan,” Izuku whispered against his lips.

“Yeah,” Katsuki murmured back, lips curling into a smirk. “Let’s celebrate your birthday properly this time, nerd.”

Izuku let out a quiet laugh, warmth radiating from him as he reached out and tangled their fingers together.

They started toward the bedroom, shoulders brushing lightly. Katsuki stole glances at Izuku’s flushed cheeks and bitten lip, at the way he seemed suspended somewhere between floating on air and crumbling under the weight of everything he felt.

Halfway there, Katsuki gave Izuku’s hand a gentle tug, pulling him to a stop.

“By the way…” He shot him a crooked grin, his own heart hammering wildly in his chest. “Nobody’s ever fucked me before.”

Izuku froze, eyes going comically wide, mouth falling open in shock as a furious flush climbed his cheeks.

“W-what?!” he squeaked.

Katsuki barked out a laugh as he drank in Izuku’s utterly scandalized expression.

“Yeah, you heard me.”

Izuku’s cheeks blazed red as his hands flailed for a second before he covered his face with a groan.

“Oh my god… Kacchan… why would you tell me that now?!”

Katsuki just smirked wider, leaning in to press a quick, teasing kiss to Izuku’s temple.

“‘Cause your face right now? Fuckin’ priceless.”

Izuku let out a strangled sound somewhere between a growl and a laugh, and Katsuki chuckled, tugging him gently forward again.

“C’mon, birthday boy,” he murmured. “Time to make some new firsts.”

It wasn’t a great day to be stuck in the office buried under mountains of goddamn paperwork. Well, it was never a good day for Katsuki to stay chained to his desk, but today, in particular…

Fuck, even just sitting hurt.

Not that he regretted a single second of last night. Hell no. Every time his brain flickered back to it, the heat of Izuku’s body pressed close, the sounds ripped from his own throat, he couldn’t stop the shiver that snaked down his spine. Or the way his cock twitched, eager and traitorous beneath his costume pants.

Shit. All he wanted was to blow this entire pile of paperwork to ashes, storm out of the agency, and run straight to UA. He wanted Izuku on him again, wanted those hands grabbing his hips, pushing him into a wall, or shoving him flat against the nearest surface. Didn’t matter if it was a restroom, an office, a locker room… he’d take it anywhere. He needed it again, and he needed it now .

The thought barely formed when the door to his office slammed open.

Katsuki tore his eyes away from the papers scattered in front of him.

Monoma was standing there, wearing the world’s smuggest grin.

“You!” Katsuki exploded, shoving his chair back so hard it screeched across the floor. His palms slapped the desk as he shot to his feet, his entire lower half grateful for the reprieve. “You damn bastard!”

He barely got the words out before he noticed someone else lingering behind Monoma.

A girl. Young, couldn’t be more than twenty. Brown hair, brown eyes, shoulders hunched, gaze fixed firmly on the floor.

“Is this how you say thank you to your most magnificent and selfless friend?” Monoma said, spreading his arms like he was on a stage. “Midoriya wasn’t so harsh to me when he texted this morning.”

“The fuck d’you mean?” Katsuki snapped, glaring so hard it was a miracle Monoma didn’t spontaneously combust.

“Well well well,” Monoma gestured grandly to the girl behind him, who shrank even further, like she was trying to disappear into the folds of her clothes. “Allow me the honor of introducing the brilliant Pastbreaker.”

Katsuki’s eyes snapped to her again. She didn’t meet his gaze, didn’t even glance his way. Just stood there, trembling with nerves so tight they practically hummed in the air. 

For a second, a very brief second, Katsuki almost felt bad for her. Almost.

Because the only person on his detonation list right now was still very much Monoma.

“She was generous enough to lend me her quirk last night,” Monoma continued, puffing himself up like a goddamn peacock. “It’s called Hindsight. Isn’t that poetic? It allows the user to travel into the past to let’s say… gain clarity. Reflect. Heal. That sort of thing.”

Heat exploded in Katsuki’s cheeks. “So… you actually set me up??”

“Set up sounds so vulgar, ” he said, lifting a hand in mock offense. “Why must you always be like this? Think of it as… an opportunity. An intervention.”

Katsuki stared at him, jaw tight.

“Did- did you see anything?” he asked, ears burning.

Monoma shook his head sharply, a shiver of revulsion rippling through his entire body. “Oh, no. No. God, no. Hindsight operates independently. And even though I can only borrow quirks for five minutes, this one, once activated, just… runs its course until it’s done. Using it drained me considerably; but that’s simply from the energy used for time travel. No visual or audio feedback involved, thank goodness.” He grimaced, giving a dramatic little shudder, as if the very idea physically repulsed him.

“Just-” Katsuki began, voice low, wrestling with tangled feelings. His eyes flicked to Pastbreaker, who looked a little more at ease now, though far from relaxed. “Why the fuck would you do that?”

Monoma’s grin faltered. His eyes dropped to the floor, and for the first time in a long damn while, Katsuki saw a hint of vulnerability crack through the showman’s mask.

“I couldn’t stand the miserable look on your face any time you, Midoriya, and Uraraka were in the same room,” Monoma murmured. His voice was softer than Katsuki had ever heard it, stripped of its usual theatrics. “And, at the end of the day… you of all people don’t deserve another crushing… heartbreak.”

Katsuki sucked in a breath. 

Oh fuck.

This motherfucker.

This damn motherfucker.

Had Katsuki really been that fucking obvious all this time? How the hell had Monoma picked up on something like that?

Sure, Monoma had taken to hovering around ever since the war. Checking in. Dropping by without reason. Sending random texts that were half insults, half genuine concern. Always showing up at the worst (or maybe the best) possible moments. And now…

And now…

Holy fuck.

A soft voice sliced through his spiraling thoughts.

“I’ve been so happy to help Phantom Thief,” Pastbreaker piped up, her tone hesitant but earnest. “I know he really wants to see you smile, Dynamight.”

Katsuki blinked hard. His eyes snapped back to Monoma, who still refused to look up, shoulders locked tight. His face was half-turned away, hiding an expression that looked, against all laws of nature, almost shy.

Tears welled up unbidden, blurring his vision.

Fuck, fuck, fuck!

He couldn’t believe this. Couldn’t process the swirl of gratitude and embarrassment squeezing his chest. 

“Get- get out of here,” Katsuki said at last, voice hoarse, his hands trembling. “Before… before I…”

Before I fucking fall apart in front of you.

Monoma seemed to understand instantly.

“Okay, okay,” he said quietly. A faint smile flickered over his lips. “Come on, Pastbreaker.”

Katsuki watched as Pastbreaker gave him a tiny, timid smile of her own. Monoma followed, his steps slow, his head slightly bowed, as though weighed down by everything left unsaid.

But as Monoma reached for the handle to close the door, Katsuki surged forward on impulse, grabbing the knob and halting it midway.

The gap left open was narrow, but enough for Katsuki to see Monoma pause, eyes wide with surprise.

Katsuki didn’t look Monoma fully in the face, but he couldn’t stop the smile tugging at his own lips. 

There were lots of things Katsuki wanted to say to him; but the only words he could manage were simply, “Thank you.”

Monoma blinked, caught somewhere between shock and warmth. He didn’t try to speak, though. He just nodded, his expression soft.

Katsuki let go of the door, and Monoma eased it shut, leaving the room quiet once more. He stood there, staring at the grain of the wood, feeling the tension drain slowly from his shoulders. The faint smile lingered on his lips, trembling at the edges but refusing to fade.

It was just him, in his office.

Yet never had he felt less alone.