Chapter Text
It’s still dark when Todomatsu wakes up, drowsy and confused. Osomatsu is glued to his left side, arms wrapped tight around his middle and cheek pressed uncomfortably into Todomatsu’s shoulder, fast asleep, and Todomatsu releases an irritated sigh as he begins the process of untangling his brother’s limbs from his body, frustrated over being woken by such a stupid thing. He’s managed to get one of Osomatsu’s arms off of him when he notices something amiss, and he pauses, sitting up as best he can in Osomatsu’s restricting grip. It only takes seconds for him to realize that the problem is a foreign scent in their room, and he’s immediately on edge, roughly shoving Osomatsu off of him so he can investigate properly. Osomatsu whines in protest, but rather than waking up he just turns around, wrapping himself around Choromatsu instead.
“Useless older brother…” Todomatsu mutters under his breath, forcing back his irritation so he can focus properly on the scent. There’s something familiar about it, although he’s sure he’s never smelled it before, and it only serves to aggravate the anxious knot developing in the pit of his stomach as he looks around the room, feeling frustrated when he finds nothing different. Their room looks the same as it did when he went to sleep; it’s obvious no one has come or gone, so where it the weird smell coming from?
A quiet whine from his right grabs his attention, and as he glances over at Karamatsu it suddenly hits him; the foreign smell is coming from him. The tension drains from Todomatsu’s muscles immediately, his territorial anger being replaced with confusion and concern as he turns to his older brother, tentatively moving to touch Karamatsu’s shoulder. He can feel the heat radiating off of Karamatsu before he even touches him, and he stops, pursing his lips as he struggles to make sense of the situation. The answer is clear, of course. There’s only one thing this can be, and as Karamatsu whimpers in his sleep Todomatsu can’t help smiling softly; Karamatsu has finally presented as an omega.
Todomatsu’s joy is short-lived as this revelation brings on a wave of concerns. Karamatsu is in heat. His first heat. And their mother and father are away. None of the Matsuno children know how to care for an omega through their first heat; Todomatsu can’t even remember his, he was so disoriented throughout the whole week, and he knows Jyushimatsu can’t remember his own either. Todomatsu can’t help the fear that grips his heart as he realizes this could go so, so wrong. How are they supposed to help Karamatsu through this?
A confused groan from Karamatsu’s other side breaks Todomatsu from his thoughts, and his gaze shifts from the fitful omega to Ichimatsu, who is staring up at the ceiling with a sleepy expression, brow furrowed in a small frown. His gaze shifts to the left, eyes falling on Todomatsu briefly before they shift to Karamatsu, and for a moment he just stares. Todomatsu can see the gears struggling to work in Ichimatsu’s head, eyes unblinking as he stares at their elder sibling. Another whine from Karamatsu seems to jolt Ichimatsu from his drowsy state, and before Todomatsu can blink Ichimatsu is out of bed, several feet away as a mix of confusion and arousal swims in his eyes. He looks pitifully lost, eyes flicking desperately between Todomatsu and Karamatsu, like he’s trying to make sense of the situation through the hormones fogging his mind.
It’s obvious that Ichimatsu is in no position to help Todomatsu figure out how to deal with this situation properly, so Todomatsu decides to wake the only one amongst them who he trust to have any helpful knowledge. He turns away from Karamatsu and Ichimatsu, brow furrowing as he stares at his remaining alpha brothers, who are tangled up in each other. Well, Osomatsu is tangled up, at least; Choromatsu is laid there with his limbs pinned to his sides by Osomatsu’s embrace, looking annoyed even in sleep. It’s endearing.
“Choromatsu-niisan.” Todomatsu whispers, working on detaching Osomatsu from the third son while Choromatsu mumbles indistinctly, still very much asleep despite the commotion. Osomatsu whines as he’s pried away from the warmth of his current victim, and this time he does wake up, eyes half-lidded drowsily as he pulls weakly against Todomatsu’s grip on him.
“Totty, lemme sleep…” He says, a childish whine in his voice as he tries to latch onto Choromatsu again. Todomatsu keeps his grip tight, though, and Osomatsu gives up quickly, too tired to put up a fight. At least until the scent of Karamatsu’s heat hits him. Then he’s jerking up, his head nearly knocking into Todomatsu’s nose as he looks around, eyes wide in confusion. “Who’s that?” He asks, pulling out of Todomatsu’s grip before the youngest can answer to find the answer himself. Todomatsu ignores him, allowing Osomatsu to crawl over to Karamatsu as he turns his attention back to Choromatsu, shaking his shoulder.
“Choromatsu-niisan, wake up.” He snaps, tone short as his patience wears thin. Choromatsu’s brow furrows before he cracks an eye open, glaring up at Todomatsu through the dark of their room. It’s definitely too early for him to be woken up.
“What do you want?” Choromatsu asks, annoyed, moving to turn onto his side, away from his brother. Todomatsu presses a hand on his shoulder before he can get far, keeping him in place, and he lets out an aggravated growl, ready to scold his brother when he notices the scent of the foreign heat. His gaze softens to one of confusion, and he looks up at Todomatsu expectantly, waiting for him to explain. Todomatsu relaxes his grip immediately, relieved that he’s finally got Choromatsu’s attention.
“Karamatsu-niisan’s in heat.” Todomatsu whispers, and Choromatsu’s brow quirks in surprise, but he doesn’t say anything. Instead he sits up, blinking slowly as his sight adjusts to the dark before he looks over to the brother in question. Osomatsu is sitting at Karamatsu’s head, leaning over him as his fingers run through Karamatsu’s hair gently, cooing softly at the sleeping omega. It wasn’t the behavior Todomatsu expected from his eldest brother, but he clearly underestimated Osomatsu’s instincts when it came to an omega’s first heat. Karamatsu looks far more relaxed now than he had when Todomatsu first woke up, even if he is still whining quietly every so often.
“How long has he been like that?” Choromatsu asks, slipping out from under the covers to sit beside Karamatsu, placing the back of his hand on Karamatsu’s cheek, brow furrowing in concern immediately. Karamatsu is hot. Which is normal, he supposes, but Todomatsu and Jyushimatsu are never this warm during their heats. Were they during their first? He can’t remember.
“Since before I woke up, I guess? I don’t know, what time is it?” Todomatsu asks, irritated at the question. How the hell was he supposed to know that? He’s only been awake for ten minutes!
“He needs to cool down.” Osomatsu says, pulling Choromatsu and Todomatsu’s attentions to him. They hadn’t realized he’d even been listening. There’s something about the look on Osomatsu’s face, happy and loving and so, so caring, that has both their hearts skipping a beat, and Todomatsu can’t help smiling as he stands up.
“I’ll go get some towels.” He says, before he leaves the room. Choromatsu remains in place, leaning back on his hands as he watches Karamatsu quietly. He wonders if they should wake him, or if he’s better off asleep. He supposes it doesn’t make much difference; he’s got a week of this to look forward to, he’ll wake up eventually.
“Is he okay?” Choromatsu glances up when Ichimatsu speaks, his voice quiet. He’s calmed down by now, settling about a foot away from his siblings with a concerned frown. His gaze is fixed on Karamatsu, who’s grown quiet under Osomatsu’s attention, his breathing light even as sweat trickles down his cheek.
“He’s great.” Osomatsu responds before Choromatsu has a chance to, and he looks so pleased. Choromatsu admires him for being so calm, his attitude soothing the anxious ball in his stomach. Osomatsu seems to have the same effect on Ichimatsu, who visibly relaxes further, shifting closer to his siblings.
“He’s really warm…” Ichimatsu mumbles, looking uncertain as he strokes Karamatsu’s hand gently before he holds it, entwining their fingers together. Karamatsu keens softly in his sleep, brow furrowing slightly before relaxing again, his breathing deep and even. Osomatsu hums in agreement, looking towards the door as Todomatsu walks in, arms full with a bowl of cold water and towels. Choromatsu jumps to his feet to help him, taking the bowl from Todomatsu’s hands before they both return to the futon, Choromatsu placing the bowl carefully beside Osomatsu. Todomatsu places the towels in a neat pile beside it, within easy reach.
Choromatsu sits back down beside Karamatsu as Osomatsu dips a towel in the water, Todomatsu coming to sit between his legs, back to Choromatsu’s chest. Choromatsu hums softly, wrapping his arms around Todomatsu’s waist as he rests his chin on the omega’s shoulder, watching as Osomatsu wrings the towel out, brow furrowed in concentration as he lays it over Karamatsu’s forehead. Karamatsu murmurs softly in his sleep, but the cool towel seems to soothe him, and Osomatsu smiles softly, cupping Karamatsu’s face gently as he strokes his thumbs across Karamatsu’s cheeks, humming quietly to his sleeping brother. There’s something only vaguely familiar about the tune, and Choromatsu suspects it’s one of Karamatsu’s original songs. How stupidly endearing.
“Osomatsu-niisan is being surprisingly reliable.” Todomatsu whispers into Choromatsu’s ear, body twisting in Choromatsu’s hold so he can look at him, an amused smile on his lips. Choromatsu grins back, nodding as he nuzzles against Todomatsu’s cheek, warm affection spreading through him.
“He is.” He agrees, nuzzling into Todomatsu’s neck before he shifts his gaze back to Karamatsu. Movement to his right grabs his attention, though, and he glances over to see Jyushimatsu waking up, drowsy for all of two seconds before he’s leaping out from under the covers, fully energized. He hurries over to his brothers’ sides, plopping down next to Ichimatsu as he looks down at Karamatsu, eyes wide with curious excitement.
“What’s going on? Karamatsu-niisan smells weird; is he okay?” He looks to Ichimatsu for his answer, bouncing in place as he waits eagerly. Ichimatsu smiles softly in response; Jyushimatsu’s presence has that effect on him. He holds Jyushimatsu’s hand with his free one, squeezing gently, and Jyushimatsu stills immediately, still obviously excited.
“Karamatsu is in heat.” Choromatsu says, drawing Jyushimatsu’s attention over to him. Jyushimatsu brow furrows, looking abnormally serious as he looks down at Karamatsu, placing a hand on his knee through the blanket.
“Karamatsu-niisan is an omega?” He asks, looking back at Choromatsu, who nods slowly. Jyushimatsu’s face immediately splits into a wide grin, and he leans against Ichimatsu, obviously trying to contain himself. “That’s great! I’m so happy!” Ichimatsu hums in agreement, releasing Jyushimatsu’s hand so he can wrap an arm around him in a hug. Jyushimatsu snuggles into the contact immediately, his hand joining Ichimatsu’s on Karamatsu’s hand, squeezing gently. “I’m so glad, niisan.”
“Do you think he’s going to wake up soon?” Todomatsu asks, yawning as he does. He’s sure he only got a couple of hours of sleep before he was woken; as happy as he is over Karamatsu, he really wants to go back to bed.
“Probably not ‘til morning.” Osomatsu replies, looking over at Todomatsu with an affectionate grin. “You guys can go back to sleep, if you want. He’ll be okay.” Todomatsu looks uncertain at the suggestion, glancing down at Karamatsu for a moment. The sleeping omega looks peaceful, though, and after a moment Todomatsu nods, crawling out of Choromatsu’s lap to return to his spot beside Karamatsu. Choromatsu follows him, slipping into Osomatsu’s spot to cuddle against Todomatsu.
Todomatsu hums softly as he turns to give Choromatsu a gentle kiss, whispering a quiet ‘goodnight’ against his lips before he turns back to face Karamatsu, twining his fingers with his elder brother’s gently. Choromatsu snuggles against his back in response, an arm wrapping around Todomatsu’s waist as he nuzzles into his neck. They’re both asleep within moments, and Osomatsu smiles affectionately, brushing Todomatsu’s hair back before he turns to his remaining siblings.
“You guys should go to sleep too.” He suggests, smiling softly. Ichimatsu looks uncertain for a moment, gaze flickering up to Karamatsu’s face, but Jyushimatsu is pulling him to his feet before he can make any protest, clearly eager to get back to sleep.
“Okay, niisan!” Jyushimatsu agrees, pressing a wet kiss to Osomatsu’s lips before he hurries over to his spot, gesturing for Ichimatsu to follow. Ichimatsu still looks uncertain, but Osomatsu pats his leg gently, grinning up at him.
“It’s okay, I got this. You go sleep.” Ichimatsu hesitates for a moment more before he nods slowly, leaning down to kiss Osomatsu before he joins Jyushimatsu on the opposite side of the futon, slipping into Choromatsu’s usual spot. Jyushimatsu is wrapped around him immediately, face buried into Ichimatsu’s neck, and Osomatsu smiles softly at the sight, watching the pair for a moment more before he shifts his attention back to Karamatsu. Karamatsu is still asleep, breath light and even, and Osomatsu feels his heart swell in his chest.
“I’m so happy.” He murmurs softly, and he presses a kiss to Karamatsu’s forehead before he slips into bed beside him, leaning his weight on his arm so he can still watch his brother, determined to stay awake for him. He grips Karamatsu’s hand gently with his free hand, squeezing softly as he rests his cheek in his other palm, smiling softly. “We’ll take care of you, I promise.”
Karamatsu doesn’t stir from his sleep, but Osomatsu swears he can feel him squeeze his hand gently in return, and he can’t wait for morning to come.