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Genya sits cross-legged on the rooftop, a half-eaten bento in his lap, the warmth of the afternoon sun pressing against his back. Across from him, Tanjiro and Nezuko are mid-conversation, their words blending into the steady hum of the breeze. It’s peaceful up here, a nice break from the chaos of the school day.
Then Nezuko sighs, dramatically flopping onto her back. “I hate Iguro’s class.”
Tanjiro blinks, caught off guard. “Chemistry? But you love math.”
“Exactly!” Nezuko huffs, sitting up again. “Everyone said the hardest part of chemistry was the math—but the math is fine! It’s him I can’t stand!”
Genya snorts, shoving another bite of rice into his mouth. “Iguro acts exactly like Sanemi, and you love him.”
Nezuko waves him off, rolling her eyes. “It’s different.”
"How?" Genya asks, raising a brow.
Nezuko doesn’t hesitate. “Sanemi yells because he cares. Iguro looks like he’s calculating whether we’re worth the oxygen we’re breathing.”
That earns a laugh from Tanjiro, but Nezuko is just getting started.
“I swear, he doesn’t teach us about covalent bonds like he’s explaining chemistry. He teaches it like he’s analyzing a toxic relationship.”
Genya lets out a short chuckle, shaking his head.
“I’m serious!” Nezuko insists, grinning now. “And he always looks at us like he’s calculating the exact amount of cyanide he’d need to take us all out.”
It’s not even that funny. It really isn’t. But something about the way she says it—so deadpan, so utterly exasperated—rips a laugh straight from Genya’s lungs. A real, full-bodied laugh, the kind he doesn’t have very often.
And he can’t stop.
His shoulders shake as the giggles overtake him, breathless and bordering on hysterical.
Then something shifts.
His laughter cuts off with a sharp, wheezing inhale. Suddenly, his chest feels too tight, like a fist has wrapped around his lungs and refuses to let go. He tries to suck in a breath, but it’s like he’s breathing through a straw—thin, ineffective.
Shit.
Panic surges through him instantly. He tries to stand, but the moment he pushes himself up, his knees buckle, sending him straight back down onto the rooftop. His hands clutch at his chest, fingers trembling as he gasps for air.
Nezuko and Tanjiro move at the same time.
“Genya!” Tanjiro’s hands grip his shoulders, steadying him.
Nezuko kneels beside him, her voice urgent. “What’s wrong?!”
Their voices are muffled, drowned out by the high-pitched ringing in his ears. The only thing he can hear clearly is the ragged, wheezing sound coming from his own throat.
Tanjiro asks something again, and this time, Genya catches it— “Where’s your inhaler?”
And that makes the panic spike even worse.
Because he doesn’t have it. It’s sitting on his desk at home.
No, no, no—
Genya gasps, his body fighting for air, but no matter how hard he tries, it’s not enough. His vision is swimming, blurred at the edges, but he forces his mouth to move, forces himself to rasp out the only name that comes to mind.
“S—San—Nemi—”
He barely manages to choke it out, but Tanjiro must understand, because in the next second, he’s gone.
Genya can’t see much through his haze of panic, but he hears it—footsteps hitting the rooftop, faster than he’s ever heard anyone move before. Then nothing.
Nezuko shifts beside him, moving quickly, positioning herself directly in front of him. Genya barely registers it, barely processes anything past the tight, crushing grip of his own lungs refusing to work.
But then her voice cuts through the panic just enough to reach him, soft but firm.
“Genya, look at me.”
He can’t. His eyes are screwed shut, his vision blurred with the heat of tears, his whole body trembling with the desperate, failing attempt to drag in a proper breath.
“Breathe with me.”
He tries.
He really does.
But his lungs burn, like fire licking through his ribs, like he’s been running for miles on nothing but fumes. Each inhale is shallow and unsteady, a cruel imitation of what breathing should be, and his chest aches with every second that passes.
Nezuko doesn’t let up.
Her hands are on his, firm and grounding. She’s close enough that he can feel the warmth of her, the steady rhythm of her own breath. She inhales—slow, deep, controlled.
“Like this,” she says, exhaling just as slow. “In for four, out for four. Just follow me, okay?”
He clenches his jaw, shaking with effort, but he nods—just barely.
“Good. Again.”
She repeats the pattern. Again and again. And Genya tries to match it, tries to follow, but his body won’t cooperate. The panic is still there, tight in his chest, squeezing around his lungs like a vice, but Nezuko’s voice doesn’t waver.
“That’s it. You’re doing good.”
It’s a lie. He knows it is. He’s not doing good—he’s barely breathing. But still, her voice helps. A little.
It keeps him from completely unraveling. Keeps him from falling into the spiraling terror clawing at his chest. The world still feels too distant, his body still too heavy, but at the very least he doesn’t feel like he’s going to pass out any second now.
“Just like that. You’re okay, Genya.”
His head feels too heavy, tilting forward slightly as he forces himself to match her breathing pattern. He hears her inhale, slow and steady, and he tries to follow, his own breath coming in broken gasps. But it’s still too tight, still not enough. His nails dig into his palms, frustration coiling in his chest.
Nezuko doesn’t let go of him. She shifts closer, pressing his hands between her own, her thumbs brushing over his knuckles.
“It’s going to pass,” she murmurs, her voice so sure, so calm. “I promise. Just keep going.”
He wants to believe her.
And maybe he does, just a little.
Because the panic isn’t getting worse. The ringing in his ears is still there, but it isn’t drowning everything else out anymore. His gasps are still shallow, but they don’t feel quite as desperate now. His chest still aches, but the burning has dulled just slightly.
There’s a rush of footsteps.
Heavy, fast, desperate.
Genya barely registers it at first, too focused on the shallow, stuttering rhythm of his own breaths, on the way Nezuko’s voice keeps him tethered to something solid.
But then he hears it—his name, rough and frantic, tearing through the haze of suffocating panic.
“Genya!”
Sanemi.
Genya barely has time to process it before there’s a blur of movement in front of him. Nezuko shifts back, making space as Sanemi drops to his knees beside him, his hands gripping Genya’s shoulders so tightly it nearly knocks the breath from him—what little breath he has left.
“I got it—I got it, just—just hold on—”
Sanemi’s voice is strained, raw like he’s been running, like he’s been tearing through the halls at full speed. Genya barely has the presence of mind to wonder just how fast he got here.
Cool metal presses against his lips.
“Breathe in. Now.”
Genya obeys without thinking, pressing his lips around the mouthpiece and inhaling as best he can. It’s shaky, weak, but it’s enough to take in the sharp, bitter medicine.
Sanemi counts the seconds under his breath.
“Hold it—just a little longer—okay, now let it out.”
Genya exhales, his whole body trembling as his lungs still fight against him. He barely gets a second to recover before Sanemi is pressing the inhaler to his lips again.
“Again. Breathe, dammit.”
Another inhale. Another exhale. The tightness in his chest is still there, still burning, but the iron grip of panic starts to loosen. His breaths are still rough, still uneven, but air moves now, fills his lungs a little easier.
Sanemi’s grip stays firm on him the entire time, his hands still clutching his shoulders, steady, grounding. He doesn’t say anything at first—just watches. Waiting.
Genya drags in another breath. It’s still shaky, still too fast, but at least it’s there.
“Shit,” Sanemi mutters under his breath, voice dropping lower, softer. “You scared the hell outta me.”
Genya tries to respond, but all that comes out is a weak, rasping breath.
Sanemi exhales sharply, pressing a hand over his own face for a second, like he’s trying to push down the lingering panic in his chest. Then, slowly, his grip on Genya’s shoulders eases—not pulling away completely, but not so tight anymore, like he’s just making sure Genya stays there, stays solid.
Genya swallows, blinking hard as his vision slowly starts to clear.
His body still feels weak, his breaths still uneven, but he’s breathing.
“You alright?” Sanemi’s voice is rough, quiet, and tinged with worry. It almost doesn’t sound like him at all.
Genya nods weakly, swallowing around the tightness in his throat. “Yeah,” he rasps out, barely audible even to his own ears.
Sanemi’s eyes narrow slightly, like he doesn’t fully believe it, but he doesn’t push. Instead, his grip tightens just a fraction, protective and reassuring. “Just keep breathing,” he says softly. “You’re alright now.”
Genya does, letting himself relax into the sound of his brother’s voice, the slow and steady weight of his hand. Beside them, Nezuko hasn’t moved. She sits quietly, eyes wide and concerned, her gaze flickering between the two of them.
“Thank you,” Genya manages to murmur, glancing at her. She smiles softly, relief obvious on her face.
Sanemi exhales, dragging his free hand roughly over his face again, tension visibly melting from his shoulders. He’s still breathing a little too hard, clearly trying to calm himself down.
“Next time,” he starts gruffly, though his voice holds none of its usual edge, “Don’t leave your damn inhaler at home, got it?”
Genya nods again, embarrassment warming his face as he drops his gaze to his hands. He can’t believe he forgot—he never forgets something this important.
“Sorry,” he whispers.
Sanemi sighs softly, shaking his head. “Forget it. Just don’t do it again.”
Genya glances up at him again. Sanemi’s jaw is still tight, expression still tense, but there’s something softer around his eyes. Something worried. Something gentle, in a way Sanemi rarely allows himself to be.
Tanjiro finally returns, his own breaths heavy, a slight sheen of sweat on his forehead. His eyes dart between them, taking in the way Sanemi’s still gripping Genya, the tension in his shoulders, the exhausted look in Genya’s face.
“Is he—”
“He’s fine.” Sanemi cuts in, not looking away from Genya.
Tanjiro watches for a second longer, then nods, easing down onto his knees beside Nezuko.
“I got the nurse,” he says. “She should be here soon.”
Sanemi barely acknowledges it. He shifts his grip, one hand moving to squeeze the back of Genya’s neck, firm and steady. “You with me?”
Genya huffs out something that’s almost a laugh, weak but real. “Yeah.”