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Snow in Tokyo was never supposed to stick.
That was Senku’s first complaint of the day, delivered flatly while staring out the apartment window with a mug of coffee gone cold in his hand.
“It’s statistically unlikely,” he said. “Urban heat islands, atmospheric particulates, elevation—”
“It’s sticking,” you cut in, already pressing your face closer to the glass. “Look. The cars are slowing down.”
Senku followed your gaze, bright red eyes narrowing just slightly. Outside, the street below was blanketed in white, tire tracks carving imperfect lines through the slush. A kid in a puffer jacket was already attempting to roll a snowball the size of his torso. Someone else slipped, caught themselves, and laughed.
Senku clicked his tongue. “Annoying.”
“You’re smiling.”
“I’m not.”
You turned around, arms crossed, eyebrow raised in the universal language of try again. Senku sighed like a man forced to admit an inconvenient truth.
“Fine. It’s… aesthetically tolerable,” he said. “And mildly interesting from a meteorological standpoint.”
You snorted. “You love it.”
He didn’t answer that—just leaned down and stole a quick kiss from the corner of your mouth, tasting faintly of coffee and sugar, before turning back to the window.
Dating Senku Ishigami meant learning that affection often came sideways.
The apartment smelled like butter and sugar within the hour.
You’d insisted on baking cookies.
Senku had insisted on precision.
He also insisted that baking was a science. One that he’d never mastered.
Which was how the two of you ended up at the kitchen counter, surrounded by labeled bowls, a digital scale, and a printed spreadsheet he’d taped to the cabinet door titled:
COOKIE OPTIMIZATION PROTOCOL: CHRISTMAS VARIANT
“Why does it have error margins,” you asked, peering over his shoulder.
“Because baking is chemistry,” Senku replied, cracking an egg one-handed into a bowl without looking. “And chemistry demands control variables.”
“You’re making cookies.”
“And I’m doing it right.”
”For Saint Nick’s sake, you are in a kitchen, NOT in a lab.”
”You say tomato, I say Solanum lycopersicum.” He pointed the whisk at you indignantly.
You sighed and watched him work—rolled-up sleeves, flour dusting his forearms, hair pulled back loosely with one of your scrunchies because you’d threatened to leave if he got egg in it again. He moved with the confidence of someone who had memorized reactions down to the molecular level, but there was something almost domestic about it now.
Familiar.
Comfortable.
You nudged his hip with yours. “You know people usually bake cookies to relax.”
“I am relaxed.”
“You’re muttering.”
“That’s thinking.”
“That’s stress.”
He smirked without looking at you. “You like it.”
You did. Unfortunately.
You grabbed a cookie cutter shaped like a star and pressed it dramatically into the dough. “So. Christmas.”
Senku hummed. “Capitalist invention. Historically inconsistent traditions. Pine trees indoors are a fire hazard.”
“And yet,” you said sweetly, “you bought lights.”
“They were on sale.”
“And wrapped presents.”
“Efficiency.”
“And agreed to bake cookies with me,” You glanced at the various baking supplies spread across the counter, almost as if realizing you hadn’t contributed a thing. “Scratch that, more like agreed to bake cookies for me.”
He paused, finally turning to look at you. His expression softened—just a fraction, but you knew him well enough to catch it.
“Data indicates you get happier when we do stupid seasonal rituals,” he said. “I like that outcome.”
Your chest did a stupid little thing.
You leaned in and kissed his cheek, leaving a smudge of flour there on purpose.
“Hopeless,” you said.
“Kekeke. You’re worse.”
Unlike Senku’s previous baking attempts—which usually ended in something closer to charcoal than food—what came out of the oven this time were genuinely edible, holiday-shaped cookies.
Perfect, even.
You eyed them suspiciously, then glanced at Senku. He shrugged, far too casual about the miracle.
He must’ve gotten lessons from Francois.
They had golden edges, soft centers, evenly spaced chocolate chips—no burnt bottoms, no weird spreading, no tragedy. Senku inspected one like a scientist reviewing a peer’s work, then nodded.
“Acceptable.”
You bit into one immediately and groaned. “Oh my god. These are illegal.”
“See?”
“Don’t get smug.”
Too late.
You flicked flour at him.
It hit his cheek.
He blinked.
Slowly.
“…You’ve chosen violence.”
“Oh, don’t be dramatic—”
He scooped flour with surgical precision and tossed it back at you.
The kitchen descended into madness.
Flour streaked the counter, the floor, your sweater. You shrieked when Senku lunged for you, grabbing your wrist with one hand while dusting your nose with the other, eyes alight with something mischievous and bright.
“You started it,” he said.
“You escalated!”
“You escalated, poorly.”
You tried to twist free, laughing so hard your sides hurt, and managed to smear flour across his jaw in retaliation.
He froze.
Then laughed.
Actually laughed.
A sharp, breathy sound, unguarded and rare enough that it made you pause just to stare at him.
“Wow,” you said. “I win.”
“Ten billion percent false,” he replied, but he didn’t stop smiling.
It took a while to undo the damage you’d inflicted on the kitchen. Flour clung stubbornly to every surface, to the floor, to Senku’s hair—because of course it did.
You wiped down the counters while he begrudgingly swept, grumbling about inefficiency and human impulsiveness the entire time, though he didn’t once suggest stopping. At some point, he handed you a towel without comment when he noticed your hands were cold.
By the time the kitchen was passable again, the cookies had cooled enough to eat without burning your tongue. You sat side by side at the counter, legs brushing, sharing a plate between you.
Senku dissected the texture with infuriating accuracy—crisp edges, optimal softness, acceptable chocolate distribution—while you focused more on how he kept nudging the better-looking ones toward you when he thought you weren’t paying attention.
Outside, the sky had dimmed to a pale winter blue, snow still drifting down in lazy, unbothered flakes.
That was when Senku stood, peered out the window again, and hummed thoughtfully.
“I’m going outside,” he said.
You looked up. “Why.”
“Environmental observation,” he replied immediately. “Snow density. Accumulation rate. Public response.”
“You’re lying.”
“Scientifically,” he said, grabbing his coat, “I am not.”
The snowball fight was inevitable.
Senku claimed he was “just going outside to collect data.”
You grabbed a scarf and gloves and followed him anyway.
The cold hit your face immediately, sharp and clean. Snow crunched under your boots as you stepped onto the sidewalk, breath fogging in the air. The city felt quieter—muted by white, softened.
Senku crouched, already forming a snowball with disturbingly efficient technique.
“Oh no,” you said. “Absolutely not.”
“What?” Senku sneered.
“I know that look.”
He straightened and threw.
You screamed and ducked, snow exploding against the wall behind you.
“You’re evil!” you yelled, scrambling for ammo.
“Victory favors preparation,” he called back, dodging behind a parked car.
You lobbed a snowball blindly. It missed by a mile.
“Terrible aim,” he commented.
“You’re cheating!”
“I’m winning.”
You chased him down the block, slipping once and barely catching yourself as he reached out instinctively, grabbing your arm.
“Careful,” he said, suddenly serious.
Your heart flipped.
Then you nailed him point-blank in the chest.
He stared down at the snow clinging to his coat.
“…Unacceptable.”
He tackled you gently into a snowbank, careful not to knock the wind out of you, and pinned your wrists above your head, breath coming out in short puffs, cheeks flushed red from the cold.
“You’re dead,” he said.
You grinned up at him. “You love me.”
He paused.
“…Unfortunately.”
Snow drifted down around you, catching in his hair, on his lashes. The city faded out, the world shrinking to the space between you.
He leaned down.
And kissed you.
Slow, warm, unhurried—like he had all the time in the world. Like he wanted to memorize the moment. His gloved hand slid to your cheek, thumb brushing your skin, grounding you.
When he pulled back, your nose was numb and your heart was racing.
“Merry Christmas,” you murmured.
He smirked. “Statistically speaking, it is.”
Then he kissed you again.
Snow melted between you.
And for once, Senku didn’t care about the odds.