Archive of Our Own ^beta

Chapter Text

The Hashira council room was stifling, thick with voices clashing like invisible blades. The debate over Muzan had unraveled into open combat—accusations, counterattacks, strategies colliding. Words didn’t strike; they pierced, rough edges dragging across the skin, forcing Giyuu to tense every muscle just to keep from breaking.

He kept to his corner, as always, the margins that usually offered refuge. Today they were a sentence.

I don’t belong here.

The thought wasn’t an idea. It landed like a fist in the diaphragm, a dense weight pressing on his lungs, stealing his breath. He saw the threads binding the others—respect, rivalry, camaraderie—and found himself exposed, a ghost adrift among solid bodies. Loneliness had turned into substance: bitter, thick, nearly breathable.

His wandering gaze sought an anchor. And found one.

Shinazugawa.

Standing on the far side, arms crossed, a sneer carved into his face as he baited Obanai. Contained threat, violence at rest. Giyuu had seen it a thousand times, endured it a thousand times. It had always unsettled him, always pushed him away.

But not today.

Today something different cut through him. He didn’t see scars, didn’t see fury shaping those lips. He saw the hard line of shoulders, the heavy weight of unapologetic strength. And he felt it.

It wasn’t just his hidden nature, surrendering to scent—the suppressants still held their ground. It was presence. A live current, hot, thick, like damp gunpowder in cold air. Like cypress bark after the storm. Rough, dangerous, irredeemably real. Alluring.

His breath broke. Each inhale was a struggle, a clumsy attempt to master the heat flooding his body. Not shame, not anger. Something older. Something locked away for years. And now the lock was giving.

Images struck without warning: scarred arms closing around him, a hard chest crushing his hollow, a savage presence smothering the loneliness.

Desire shook him. A tremor betrayed him. And then Shinazugawa’s violet eyes caught his. Not with rage, but with suspicion. With animal curiosity.

The stare held. Two, three heartbeats stretched into eternity. The discomfort sharpened, a knife pressed to his skin.

Giyuu looked down.

The wood before him seemed to drink the heat climbing into his cheeks. The council’s murmur returned like a distant river, yet to him everything carried the same name, the same metallic taste, the same scent of powder. The certainty tore him open: the only one who could make him feel alive was also the one who despised him.

He should have looked away. Killed the fixation before it could take root.

He didn’t.

The murmur swelled again, a river flowing far away, but he no longer heard it. He was watching still, through his lashes, masking the pursuit. He watched when Mitsuri stumbled. Watched the way Shinazugawa’s body moved before his mind, the hand that opened to catch her, the Alpha instinct revealed in a rough gesture. Saw that fleeting shadow of concern before irritation swept back to smother it.

An Alpha in the raw.

And Giyuu… Giyuu wanted him.

Wanted him until it hurt.

Wanted him until it burned.

Wanted him.

The forbidden image surfaced: himself in Mitsuri’s place, that calloused palm gripping his waist, dragging him into a body of pure life and hardness. A low voice brushing the nape of his neck: “Stay still. You’re safe.”

A ridiculous thought, a blasphemy against his own repression. And it burned. Burned deep inside him, like Shinazugawa’s presence in the room.

Shinazugawa pulled his arm free from Mitsuri’s grasp, muttered a cutting remark, turned his head—and once again their eyes met. The world stopped. There was no acknowledgment of desire, only a furrowed brow, a silent question: why was Tomioka looking at him that way? Vulnerable, stripped of his usual armor of ice.

The stare held. One heartbeat. Two. Three. And then it broke.

Giyuu dropped his gaze, heat climbing his neck until it exploded across his face. He turned on his heel and walked away. Each step echoed with the memory of that single protective gesture, branded into him like an open wound.

Each step carried him farther from Shinazugawa.

And each step felt like a mistake.

He resolved to throw himself into his missions with precision.

It was the only thing left to steady him when the world threatened to overflow.

The mission had been a disaster at its core: a minor demon, sly and slippery, had chosen a war of shadows—striking from rooftops, vanishing through alleys that opened and closed like jaws—forcing the hunters into a long, punishing chase through a town packed with tiles and chimneys. It wasn’t a battle of raw strength; it was a night hunt that scraped the body raw and gnawed at the patience, ambush after ambush leaving breath ragged and blood cold.

Giyuu, stationed on another block, reached the central square just as it all came to an end. He caught it in fragments: a girl with dark hair, a novice, her Water Breathing clumsy and trembling, chasing a trail of shadows until a trap shoved her into a dead-end alley. The sight hurt him, as if the mistake were his own.

And then a silver bolt struck.

Shinazugawa.

It wasn’t gentleness. It wasn’t rescue. It was violence, precise and measured: the night made muscle, hurling forward. The demon slammed against the wall and crumbled into shards and blood with a dry crack that rang against the stone. The air thickened with the stench of ozone and iron, mingled with the rancid sweat of battle and the foul tang of flesh charred by magic.

But what froze Giyuu’s blood wasn’t the demon’s death. It was what came after—the gesture that twisted victory into something brutally intimate.

The girl staggered back to her feet, shaking but unharmed. Shinazugawa didn’t approach with tenderness. He seized her shoulders as if gripping a fight he needed to break, fingers digging hard into the fabric of her uniform, leaving grooves that spoke louder than words.
His voice—a growl—dropped like a hammer: 

"Are you trying to get yourself killed, girl?” He said it close, so close that Giyuu could see the arc of his jaw, the grind of his teeth, and felt the unseemly urge to recoil.

Your breathing. Your breathing, whispered the silence of his own body. He watched the press of Shinazugawa’s hand, the lean of his torso, all contained force, all danger and protection curved into a single line. There was no comfort in that grip; there was command. Duty made flesh.

And yet—burning within that act—there was a heat without softness, a fire that could hold, could bear the weight.

He forced himself to look away, to count the tiles across the square, to measure steps, to recalibrate the mission in his head. But the image of Shinazugawa standing inches from the girl, his shadow falling over her like a wall, clung to him like searing iron.

It wasn’t envy. It was devastation, pure and unrelenting: the craving for that harsh protection. The hunger to be seized with that same brutality that knew how to hold. To have that ferocity turned toward him, not toward others.

He breathed. One. Two. Three. The mission was still a task to complete.

The mission was still a task to complete.

Shinazugawa’s voice rang out again.

Giyuu turned back to look.

As he scolded her, Shinazugawa’s thumbs moved. Just a second, just a touch. It wasn’t a caress. It was something older, more primal. A brief pressure, a rough rub against the tense muscles of her shoulders. A gesture disguised as reprimand, a you’re still here spoken in the raw language of brute strength.

Then he shoved her back with a dry push, turning away as if she were nothing but an inconvenience.

“Don’t make the same mistake twice,” he growled, and the night swallowed his words like rusted iron.

From the shadow of a rooftop, Giyuu saw it all.

He didn’t move. He didn’t breathe. And then the pain struck—sharp, clean, a spear straight to the chest.

It was more devastating than any jealousy or fear: the bare recognition of what he had kept buried for years.

He longed for those violent hands that, without meaning to, knew how to hold.
He longed to be taken with that desperate brutality, shaken, cursed for rushing in headlong—and in that same gesture, protected.

He longed for the fierce concern Shinazugawa buried beneath layers of rage—concern he never admitted—to be unleashed upon him.

A foolish dream. Shinazugawa would never look at him with that hardness tinged with care. To him, Tomioka was a rival, an obstacle, a ghost of cold water undeserving of protection.
If only those harsh words weren’t mere tactics, but direct reproach: Are you hurt, you idiot? Why do you always have to do it alone?

An ancient hunger, sharp and biting, burned inside him—fire trapped under ice.

Sanemi passed beneath the rooftop without lifting his eyes. The scent of storm, iron, and gunpowder lingered in the air.

Giyuu closed his eyes. Drew in that rough, protective trace that would never be meant for him.

He tried to push it away.

He truly tried.

Another mission arrived soon after: a low-ranked demon on the outskirts. A distraction, he thought. But he was wrong.

The town was still burning in panic. Demon Slayers were rallying the villagers. And Shinazugawa was already there. It wasn’t his mission, but he had arrived first. A Hashira through and through. The demon didn’t last fifteen minutes in his hands.

Giyuu stayed at the edge, watching. He expected harshness, scorn, rough treatment of the civilians. But what he saw was something else.

A trembling Omega mother clutched two children amid the ashes. The air reeked of fear, acrid and suffocating. Giyuu held his breath as she shrank from Sanemi’s figure. He braced for growls, for impatient glares.

It didn’t come.

Sanemi stopped dead, as if an invisible wall had halted him. He stepped back. Lowered himself, just barely, folding into his own tense muscles.

“It’s gone now,” he said, voice low, rasping.

He didn’t look at the woman. His gaze shifted toward the rubble instead.

The child sobbed, and Giyuu caught the raw pheromone of fear in the air. Sanemi’s back tightened even more. Giyuu understood: it wasn’t rage, it was conflict. The Alpha instinct straining against its own blade.

Carefully, Sanemi shrugged off his dust-stained cloak. He didn’t step closer. He let it fall a few paces away.

“Keep warm.”

The change was tangible. The sharp reek of gunpowder and fury receded. Damp cedar, wet earth, shelter. Rough, but deliberate. A shield.

Giyuu’s heart splintered at the sight.

The mother reached for the cloak. The earthy scent wrapped around the children, and little by little their sobs faded.

The moment broke. The scent of shelter dissolved, replaced by the familiar edge of gunpowder and rage. Sanemi’s eyes hardened when they found him.

“Tomioka.” The name, spat. A pause. “Did you come to supervise? Or were you waiting for a tea invitation?”

The mockery was expected. But it struck like a lash. Because he had seen another version, and that rough tenderness was never meant for him.

Giyuu didn’t answer. He only inclined his head and moved back toward the perimeter. The air still clung to a ghost of earth and cedar, a phantom comfort meant always for others.

Never for him.

────────

The path to the Butterfly Mansion always smelled of flowers.

To others it was a soothing perfume.

For Giyuu it was a harsh reminder, almost cruel: each petal thickened the air with a sweetness that foretold bitterness. What awaited him there was never relief, but truth. A truth that slid like poison under the tongue, shared only with Shinobu and Urokodaki.

He walked with his eyes fixed on the ground, listening to the hollow thud of his geta against the gravel. The only sound he allowed himself. His body had begun to betray him: hands trembling faintly, a damp veil blurring his senses, a fatigue that was not physical but chemical.

The price of suppressors.

As he turned the corner, the air shifted. An invisible blow, a wall crashing straight through him.

Pheromones. Not a body, not a brush of shoulders, but a torrent of dormant gunpowder and freshly split pine bark. Aggressive. Cutting. Alpha.

Fate seemed to mock him.

Sanemi Shinazugawa stood there, arms crossed, posture rigid, violet gaze raking over him with the same precision one uses to measure an enemy. Disdain, honed to a blade.

“Tomioka.” The name spat out, bitter. “Always dragging yourself around here. Don’t you have anything better to do than trample Kocho’s gardens?”

Giyuu’s heart lurched. Sanemi’s pheromones tangled around him, a sting, a summons—an instinct his body wanted to obey even as his mind refused. Lower your head. Yield. Be what you are.

“I have an appointment,” he murmured. His voice nearly broke apart before it left his lips.

Sanemi’s mouth twisted into a mocking grin.

“An appointment? With who? The koi fish?” A snort. A sharp crack of words. “At least you could make yourself useful and train the recruits. Some of us have a pack to lead.”

The word struck him.

Pack.

What he never had. What he never would. He was nothing, an emptiness disguised as an Alpha. And Sanemi, without sparing him another glance, stepped aside with contempt. He passed by, leaving behind a trail of metallic storm that slipped into Giyuu’s lungs like a thorn that could never be pulled free.

By the time he reached Shinobu’s door, his stomach was tied in knots. She greeted him with a sharp-edged smile, the kind that concealed scalpels.

“Tomioka-san,” she sing-songed, needlepoint eyes glinting. “Looks like you’ve just crossed paths with an unpleasant wind.”

He didn’t answer. The scent of wisteria and healing herbs enveloped him, a faint balm. He sank onto the stool in the dispensary. The glass vial clinked in Shinobu’s hands.

“You know,” she said in a voice light as air, heavy as lead, “Shinazugawa-san has been coming regularly since he left his brother in my care. He came again today.”

Giyuu looked up, startled. Shinobu smiled—this time for real.

“Yes. Genya no longer wants to be a Slayer. He’s an Omega, as you know. All that anger was just that: confusion, fear, the desperate need to protect him. Now he helps here. He has a gift for poisonous plants. He’s… happy.”

The vial she offered him shimmered like white bubbles adrift in a dark sea.

Suppressants. Lies. Chains.

And in that instant he understood, sharp and merciless: Genya Shinazugawa, an Omega, had found shelter. He had found a path, a way to help that made him happy. Beneath the protection of an Alpha. Beneath his brother’s wing. He had found what Giyuu would never have.

“Shinazugawa-san seems calmer,” Shinobu added, with that venom-softness that cut exactly where it hurt.

The cold glass in his hand felt like shackles. Each pill was a “no” carved into his flesh. No to protection. No to a pack. No to Sanemi.

He left the Mansion with his stomach burning. The scent of flowers had become a chokehold.

That night, at his estate, the moon carved his room with a silver scythe. The vial spun between his fingers. The rattle of pills was the sound of dry seeds. And the forbidden thought, the most dangerous one, rose from the depths of his being.

What if he stopped taking them?

What if he slipped the moorings?

What if he let Shinazugawa scent him, know him for what he was?

Would he protect him then? Claim him?

The image bled him from the inside out. Sanemi, not with insults but with that rough voice turned to shelter. Sanemi, wrapping him in pheromones of calm, not out of pity but possession. Sanemi murmuring against his neck: Enough. Rest.

Too easy. Far too easy.

But reality fell like cold steel: impossible. A discovered Omega didn’t wield swords. He didn’t stand at the front. Everything was stripped from him.

And Sabito. The memory of Sabito crushed him. The paralyzing fear, the scream etched into his bones, the Omega weakness in his skin. It was that weakness that had let him survive while Sabito died. His guilt, his sentence.

The suppressants weren’t just chains. They were his anesthetic. Without them, the pain of the world would devour him alive.

Sanemi would never see strength in him. Only weakness.

He clenched the vial until his knuckles went cold. He swallowed a pill. His throat burned.

The dream died.

The Pillar meeting confirmed it.

Sanemi was different—more focused, more unyielding. More Alpha than ever.
His pheromone, red-hot iron beneath the rain. And when those violet eyes settled on him, Giyuu felt the blade pierce.

“Tomioka.” His name again. An accusation. “Are you going to say something, or just stand there taking up space?”

The contempt was absolute. Not the chaos of an unstable Alpha. The relentless judgment of a complete one who deemed him unworthy.

And beside him, Obanai, spitting venom:
“His lack of scent is an insult. An Alpha who rejects himself is worse than a weak Omega.”

Worse. Than a weak Omega.

The hidden wound bled with every syllable.

For a heartbeat of madness, he wished the suppressants would fail. That the scent of water and wild plum would betray him. That Sanemi would turn at last and see him.

He chose silence.

He lowered his head. Accepted the role they gave him. An arrogant Alpha, a void that smelled of nothing. Better that than the truth.

Better a ghost in his corner than a broken Omega before them all.

Chapter Text

Each step was punishment.

A lament of shredded muscles, bones creaking beneath the dull echo of battle. The demon—liquid and slippery as water poured over stone—had driven him to the edge. And when it fell beneath the keen of his own blade, the price came due in blood: a deep cut along his side, a fatigue that blurred his vision and numbed his hands.

He needed Shinobu. Her sharp precision, the cold control of her needles, potions that burned like liquid fire in the veins yet returned balance. Her efficiency was merciless. No questions. No compassion. Only results.

The path to the Butterfly Mansion stretched into an endless tunnel. Every breath ripped at his opened ribs; every step thundered like a hammer, sinking him deeper in the certainty that without her he would not move another inch.

At last he pushed open the dispensary door. The air hit him—wisteria, alcohol, the bitter dyes of crushed herbs. Immediate balm. A single inhale. For an instant he believed relief brushed his skin.

It dissolved the instant he lifted his eyes and took in the center of the room; the comfort froze into a sharp ice.

Sanemi Shinazugawa was there. Not upright, not in the fierce stance that seemed to challenge the world, but kneeling. The floor welcomed him with a strange, almost reverent weight. Before him, Genya sat on a stool, bare arm reddened by the burn of a badly applied potion, every inch of skin screaming the mistake.

And Sanemi… Sanemi was devout.

With tweezers and a wad of cotton between his fingers, each movement was another world. These were not the blows that snapped demon bones, nor the charge of wrath that had defined him. It was intimate, meticulous, contained. Every touch seemed to fear causing a greater pain.

The concentration carved on his face was the same Giyuu had seen only at the edge of combat—where a mistake was a death sentence. Now it bent to cleaning a wound, to carefully lifting away charred skin. That brutal transposition—tenderness disguised as method—stole his breath.

“Stay still, you idiot,” Sanemi murmured. The voice came rough, hoarse, stripped of its usual edge. A low grunt—more like a tired wolf’s purr to its pup than a threat. “If you move, it’ll hurt more.”

Genya nodded, obedient, and his scent—green, alive, like freshly cut grass and willow bark—wove into his brother’s, an invisible bond.

Trust. Belonging. A blind, unshakable faith Giyuu couldn’t remember ever being directed at him.

The threshold became a prison. The ache in his side burned, but it was nothing compared to the pain carving through him now: a slow, unbearable stab tearing inward from his chest.

There it was.

The hidden side of Sanemi: human, fierce in his tenderness, protective to the marrow.

Giyuu saw it before him, tangible, laid bare—and turned toward another. He couldn’t look away. Genya received it. Genya deserved it. Genya was the Omega worthy of that brutal gentleness, that instinctive devotion wrapping around him like a cloak.

Not Giyuu.

Shinobu noticed first. From the back of the room, between jars and mortars, she lifted her gaze. Her eyes flicked from Giyuu to the scene between the Shinazugawa brothers, and in a flash she understood the silent storm rending him apart.

“Tomioka-san,” she said, her tone measured soft, breaking the spell of the moment. “It seems you’ve had an unpleasant time.”

The sound of his name snapped Sanemi’s head around. His gaze locked onto Giyuu’s, and the shift was instant, violent, cutting.

The pheromone of refuge vanished, replaced by the sudden, icy burst of sharpened frost.
“Tomioka,” he spat the name like a stone. “Another scratch? Looks like even the ‘strong’ ones need pampering when things get tough.”

The contrast knocked the breath from him.

Giyuu lowered his head. He couldn’t hold that stare.

“Just… need some bandages,” he murmured, barely a thread of voice.

Shinobu nodded, but the compassion shadowing her gesture stung.

As she moved forward with the kit, he couldn’t stop himself from stealing one last glance at Sanemi. The harshness was gone. The Alpha had turned back to Genya, his pheromone softened into an invisible embrace, a cloak around him.

Giyuu didn’t wait. He didn’t want questions. He didn’t want offers that were nothing more than pity in disguise. He left.

He sought refuge in an empty room. Closed the door with a click that reverberated like a slammed weight in his chest. Leaning against the wall, he let out a trembling breath he had held too long. His hands, clumsy and stiff, began cleaning the wound and wrapping his side. Every motion reminded him of what he had seen: Sanemi bending close, tending, protecting.

Not him. Never him.

The door opened without a sound. Shinobu slipped inside like a shadow. Her usual smile was gone, replaced by a clinical, cold seriousness.

“I knew your condition was worse than you claimed, Giyuu-san.” Her voice was soft, firm, leaving no room for denial. She wasn’t asking—she was stating. Her eyes dropped to the badly wrapped bandage, stained with red. “Not only physically.”

Giyuu pulled the knot tighter than necessary, feigning focus. He didn’t answer.

Shinobu sighed. Light, barely a whisper, but in the room it fell like a weight.

“Strange, isn’t it? To see what Shinazugawa-san is capable of with someone he calls his own.” Her words cut like a scalpel. She paused, gauging the edge. “His pheromone in the infirmary was rather telling. So… protective.”

The blow was brutal. Giyuu felt his stomach hollow out, sink until it was nothing but emptiness; his fingers were cold, clumsy. He had felt it. That scent of damp earth, of steady roots, of shelter.

A shelter that had never been his.

For him, there had only ever been gunpowder. Always gunpowder.

“I don’t know what you’re talking about,” he muttered, his voice hoarse, fractured, trying for a hardness that wasn’t there. He turned his eyes toward the wall, as if the plaster could swallow the lie for him.

Shinobu didn’t flinch. Her gaze moved over him with the clinical calm of someone who knows exactly where to press to reach raw flesh.

“Of course you do,” she replied with implacable softness. “We all feel it. An Alpha who’s found his center. And a leader who, when he chooses to, knows how to protect. A shame that devotion isn’t for all the Hashira.”

Each word, a needle. A needle in the wound.

Giyuu swallowed, but he couldn’t hold it in.

“He hates me,” he murmured, the confession torn out like a bone. “He thinks I’m an arrogant Alpha.”

“Isn’t that easier? Don’t you prefer his contempt over the risk of him seeing what you really are? Over the risk that he might put you in the same place as any weak Omega, one he only grants his condescension to?”

The question hit him. For a fleeting instant, the ice armor in his blue eyes cracked. Pain, rage, nakedness—all of it there, exposed.

“I’d rather his hatred than his pity,” he said, his voice rough, broken along the seams.

Shinobu studied him. Long, steady. Her edge softened just slightly, like a scalpel that had already finished its cut.

“Genya is happy here,” she murmured, quieter. “He found his strength another way. But you…” she drew in a breath, her gaze locked on him. “You carry a mask that crushes you. And seeing what Shinazugawa is capable of giving… it hurts more than any demon’s wound, doesn’t it?”

Giyuu lowered his head. There was no answer. No possible denial.

Then she leaned in, with the automatic precision of someone who knows the body as her field of study, and redid the clumsy bandage. Her fingers were firm, steady—a brutal contrast to her words.

“Keep taking your suppressants, Tomioka-san.” Her tone slipped back into something practical, yet it didn’t lose the compassion that pierced him like a sweet poison. “Hold on to your armor. If it breaks, you won’t survive what comes next. And the Corps still needs whatever strength you can manage to fake.”

The fresh bandage pressed tight against his side. Not relief—another reminder. Another prison.

Giyuu nodded slowly, feeling the weight of that cage settle against his skin.

Shinobu finished and stepped back. A brief smile, almost sincere, touched her lips. It wasn’t mockery. It was understanding.

Giyuu chose to stay that night at Shinobu’s estate. He didn’t trust his legs to carry him home, nor his mind to return whole.

Morning met him with sharp, fresh air, the scent of dew and wet wood. Yet nothing could lift the weight crushing his chest. He left the Butterfly Mansion with measured steps, each one a reminder: splintered bone, torn flesh, and the deepest wound of all—the one no bandage could cover.

He had barely made it down the path when he felt it. A blazing presence, searing, raising the hairs on his neck before the voice reached him.

“Running already, Tomioka?”

Giyuu stopped, but didn’t turn right away. His jaw tightened, his breath held as if he were keeping water in his lungs. At last he turned. Slowly.

Sanemi was there, leaning against a cedar trunk, arms crossed. The bark seemed too small beneath his weight; his body’s force outweighed even nature itself. He pushed off the tree and took one step forward. Just one. It was enough. The distance collapsed into pressure.

“It’s always the same with you,” he growled. “You show up, stare with that stone face, and leave without a word.”

His eyes cut through him.

“What’s wrong with you? Did seeing an Alpha actually doing his job make you feel small?”

True.

The word was a knife.

Giyuu was supposed to be one too. An Alpha. Protector. Leader. But next to Sanemi… he was always a poor imitation, always an impostor.

“No,” he muttered. His voice came out rough, as if his throat were filled with splinters. “I just had to leave.”

Sanemi snorted. A dry, scornful sound. His pheromones spread like thick smoke, swallowing and devouring the forest’s clean scent.

“I don’t like the way you look at me, Tomioka,” he said, now in a rasping whisper, a blade sharper than any shout. Another step forward.

A crooked smile twisted his lips—bitter, mocking.

“I thought you’d stay hidden at Kocho’s estate a little longer. But I suppose even you have a scrap of dignity left. Or is it just laziness? Easier to retreat than face anything, isn’t it?”

At last, Giyuu lifted his head, meeting those eyes that always burned him to ash.

“My wounds need rest,” he murmured. Barely a thread of voice.

The contempt scorched, acid on the skin, crueller than any open wound.

“Wounds?” Sanemi laughed—dry, hollow. “We all have wounds, Tomioka.”

Shinazugawa stepped closer. One step. Another.

And then he was in front of him, close enough that Giyuu could see the tension carved into every line of his face.

“But not all of us run off to hide like frightened pups,” his voice dropped, low, intimate, dangerous. “Or is it something else? Did Genya get to you? Does it bother you that my brother is an Omega?”

The question struck like a sudden blow.

Giyuu held his breath. His body tensed.

He was an Omega himself.

“It’s not that,” he murmured—too quickly, too hollow.

Sanemi looked at him. The rage in his eyes cracked, letting slip a different glint: sharp comprehension, almost animal. Predatory. As if for the first time he was seeing the fracture in the armor.

“No,” Shinazugawa repeated slowly, with a sudden calm that cut deeper than a shout. “Not that. Something else.”

His gaze traveled down him—not with disdain, but with a disconcerting, probing intensity. The air thickened.

“Nothing to say?” he pressed, stepping closer. Each move drove him further into a corner. “Always the same. Silence. That holier-than-thou face. It’s disgusting.”

For a moment, Giyuu’s eyes trembled. The mask nearly cracked.

He wanted to scream at him. Tell him he had no idea. That he didn’t know what it meant to carry a secret that devoured him.

He wanted to ask how he could be so blind.

How he could give all that fierce loyalty to one Omega… and nothing but ice to another.

Because yes. Genya was his brother. He belonged to him in a way no one could dispute.

Even if Shinazugawa ever found out—even if he saw him stripped bare of that lie—it would change nothing.

Still Tomioka.

An emptiness with a name.

An Omega who would never belong to him.

An Omega who had spent his whole life pretending to be an Alpha.

He lowered his gaze.

“I’m sorry,” Giyuu whispered.

Sanemi looked at him with disgust, as if that surrender were nothing more than further proof of his weakness.

“Pathetic,” he spat.

His shoulder brushed against him as he passed—barely a touch, yet enough to set Giyuu’s skin on fire. Then he walked away, leaving behind the scent of gunpowder that slowly thinned into the green of the forest.

But the emptiness did not fade.

The pain did not fade.
That remained.

Giyuu drew in a deep breath, the air raking at his chest. He resumed his path toward his own mansion, as silent and hollow as ever. And he understood that the wounds in his side were nothing compared to the one that had just opened within him.

Deep. Irremediable.

Chapter Text

The weeks dragged on, heavy and slow, like a river of murky water too afraid to flow. Training. Missions. Silence. Everything blurred into a steady, endless drip. Sometimes, he would take up the pen and write to Master Urokodaki, checking—almost fearfully—how far Tanjiro had come in his exercises. It had been a year since he’d met the Kamado siblings. Giyuu closed his eyes and drew in a long breath, letting a thin thread of hope weave through the monotony: maybe, someday, Tanjiro would be ready to take his place as the Water Hashira.

Giyuu clung to routine, letting the mechanical drown him, smothering the forbidden thoughts. But the body always betrays. The pain began as a whisper in his temples. Then it grew into a steady drumbeat—a headache that refused to yield, no matter the rest. The suppressants were failing. They crumbled like sand between his fingers, and his instincts—buried for so long—rose with a muted, relentless cry. They sought refuge. Comfort. Something, someone.

He found himself, in the broken stillness of his room, gathering pillows. Tugging at the sheets with spasmodic, compulsive motions, trying to build a perimeter—a nest.

He stopped.

His hands trembled. He stared at the tangled mess of fabric he’d made, and a wave of cold ran down his spine.

No.

Giyuu couldn’t nest.

It was a luxury. A dream of warmth and safety that had been denied him for far too long. His biology—that part of himself he’d always fought to drown—was crying out for a cycle. A heat that the chemicals, those bitter sentinels, had denied him again and again.

He had no choice. He needed something stronger. And only Shinobu could give it to him—usually, without questions.

The walk to the Butterfly Mansion crawled like a knife beneath the skin. Each step hammered inside his skull, each breath reminded him of the weight of his deceit.

His muscles were lead, stone—a burden he could barely drag. And the heat—a fire beneath the skin, a terrible fever that grew, that pulsed behind his temples, that made his blood feel too hot, too near. He pushed open the laboratory door. And the scent—the wisteria—hit him.

Once, it had been calm. A sigh. Now it was molten iron.

Liquid fire racing through his veins. A perfume that lodged itself in his throat, in his chest. It forced his eyes half-shut, made him see the world through a burning slit. He swallowed. Swallowed air violently, his jaw clenched so tight it hurt.

And there he was.

Almost like a cruel joke of fate—he was everywhere.

Shinazugawa.

Not from afar, not on a mission, not as a shadow on the rooftop. In the middle of the room, speaking with Shinobu, only a few steps away. Giyuu froze. His pulse thundered in his ears, tangled with the pain that clouded his mind, with the urge to flee before either of them could see him.

“Ah, Tomioka-san. Just in time,” said Shinobu, lifting her gaze.

Sanemi turned.

And the world seemed to stop for a heartbeat—sharp as glass.

Their eyes met. No surprise there. Only the usual disdain, but sharpened now. Magnified by closeness.

A weight in his chest.A violent beat in his ears.And the first impulse—foolish, stupid, visceral—was to bare his throat. To tilt his head. To show that Alpha he knew his place. His Omega place.Giyuu clenched his jaw, crushing the instinct with anger—cold, deliberate anger that filled his veins like ice.

Sanemi’s pheromone flooded the room. Filled his nose, his lungs. Hot iron and gunpowder. Just like always. A familiar wound.

Giyuu’s body wanted him without remedy, but the pounding in his skull turned that desire into liquid acid running through his veins.

“Tomioka,” Sanemi growled. “Seems you can’t stay away for long. Another scratch that needs coddling?”

Shinazugawa had the perfect excuse to spend hours at Shinobu’s estate: his brother.
Giyuu, on the other hand, had nothing but a lie.

He lowered his gaze. No words left his mouth. The flush of shame and pain climbed his neck—a fire he couldn’t put out.

Shinobu intervened, her voice light, composed. “He’s here for something to ease his headache. They’ve been rather strong, haven’t they?”

Giyuu gave a faint nod. Not a word.

“Headache,” Sanemi repeated, frowning as if it were a personal insult. “Maybe if you spent less time locked in your own head and more time training, you wouldn’t have those problems.”

The same old poison. But today—with his mind torn open by pain and the pheromone burning his skin—Giyuu’s mask cracked. Nausea rose in his throat, bitter and thick.

“Shinazugawa…” Shinobu’s voice was dry, edged with warning.

Sanemi gave Giyuu one last look, dragging his gaze from head to toe.

“Whatever. I’m not staying to hear his whining.”

He turned and left.
The silence he left behind was heavier than his presence.

Giyuu stayed still, barely breathing, until he heard the door close. Only then did he inhale—slowly—and lift his eyes toward Shinobu.

“Sometimes,” she said, “it’s entertaining to watch how you react to Shinazugawa. How your mask breaks. Cracks. And shows what’s underneath.”

She smiled without amusement. “Other times…”

She sighed.

“Come. I’ll prepare something stronger. And—” she paused. “Don’t let his poison worsen your wounds. The visible ones… or the ones that aren’t.”

It was a warning. Late. Useless.

Giyuu already felt sick. His stomach was a knot of ice.

Headaches were painful, yes, but never fatal. What burned in his chest, though, was.
To be so close to Sanemi and still receive nothing but gunpowder, iron, and contempt.

And the irony bit hard: even with his head ready to split, with his muscles taut and his heart strangled by desperation, Giyuu had wanted more.

More of that gaze—just once—softened for him alone.

That was the real pain.

The one Shinobu had no medicine for.

The headache subsided under the bitterness of the potion Shinobu forced him to drink, but the tension in his shoulders remained—like an overtight string on the verge of snapping.Sitting on the stool in the dispensary, Giyuu felt fragile, exposed, while Shinobu carefully cleaned the empty vial.

“Tomioka-san,” she began, her voice stripped of sweetness—flat, clinical. “This isn’t just a headache. It’s a warning. I’ve been running studies lately on your condition.”

Condition. The word almost made him laugh.

He lifted his gaze. Shinobu’s eyes were fixed on him—serious, unwavering.

“Your body isn’t a machine,” she continued. “You can trick it with suppressants for a while, but biology always claims its price. What you’re experiencing is hormonal buildup. If you keep this up, it won’t just be headaches. Your organs will start to fail—the kidneys, the liver… they weren’t designed for chronic suppression. It’s serious.”

Her words drove into the silence like nails, each one piercing the denial he’d lived in. He knew. He had felt it—an internal wear, something deeper than ordinary fatigue.

“You need to allow yourself a heat,” Shinobu said bluntly. “At least one. To release the pressure. Otherwise, you’ll kill yourself slowly. And it won’t be in battle.”

Giyuu closed his eyes.

Terror slid down his spine like ice.

A heat.To surrender to that vulnerability, to lose control, to be exposed—it was his worst nightmare.

“I can’t,” he whispered. His voice came out rough. “Not… not for three days. I can’t afford that weakness.”

Shinobu’s hand came down, cool and firm, on his forearm. Not a gesture of comfort, but of insistence.

“Understand this, Giyuu. Because you’ve repressed it so long, it won’t last three or four days. Probably a week. A prolonged, severe heat. Your body will try to compensate for everything you’ve denied it.”

He went pale.

A week.

Total ruin.

“That’s why,” Shinobu added, lowering her voice to a confidential tone, “I’m offering you one of the secure rooms in the west wing. It’s prepared for this—isolated, with discreet bars on the window, in case… in case instinct pushes you to seek something. Or someone. I can guarantee you absolute privacy. No one needs to know your true self.”

No one needs to know your true self.

The words burned.

Not in his ears—no. They burned in his heart. A sharp, stabbing ache that sealed his throat.

And yet…

The offer was both salvation and condemnation.

A refuge to endure the torment in secret, but also an admission of defeat. Acceptance of the nature he’d spent his whole life fighting.

“I can request a leave of absence for you,” she added softly, almost like a promise.

Giyuu shuddered.

A dark part of him—buried deep—trembled with anticipation at the thought of finally stopping the fight. Of surrendering, if only within the locked walls of a private room.

He looked at Shinobu. The conflict tore at him.

“I… I’ll think about it,” he managed, voice breaking.

Shinobu nodded. She didn’t press.

“Don’t take too long to decide, Tomioka-san. The body doesn’t negotiate. Losing your strength because you wouldn’t grant yourself a week of rest would be terrible. We need you.”

When he stepped outside, the world felt distant, hazy. Shinobu’s offer weighed heavier than any blade.

The days following her warning dragged like molten lead. Each heartbeat in Giyuu’s chest echoed like a drum, counting down the time until surrender. Pressure pooled at the base of his spine—a restless heat that wasn’t fever, that kept him alert, trapped in his own body like a cornered animal. His senses, dulled for years by suppressants, had awakened all at once—sharp and merciless: the air, the smells, the sounds…

Everything was too much.

Maybe that new obsession, that constant pull toward Sanemi Shinazugawa, was nothing but an echo of this raw, reawakened sensitivity.

Maybe, after surviving his heat, the longing for Sanemi would fade.

That thought took root in him—firm, undeniable.

When night fell, he returned to the Butterfly Mansion. He didn’t seek the dispensary; his path was direct, determined, toward the private study.

Shinobu was there.

“Shinobu.” Giyuu’s voice sounded strange to his own ears.

She looked at him in silence. She knew at once why he had come. She set the pen aside.

────────

The silence of the Butterfly Mansion shattered.

Sanemi burst through the doorway, Genya hanging limply in his arms. He felt the weight, but not the fatigue. The kid’s skin was so pale it looked ready to dissolve. His lips were parted, breath coming in fragments — as if every gasp cost a fight. Blood soaked through his haori, sticky and hot, and Sanemi barely registered it. He just kept moving.

He wasn’t thinking. Couldn’t think. Only that droning in his skull, that roar telling him not to let go.

His pheromones broke loose — thick, feral: iron, scorched earth, rage. Fear too, though he’d never admit it. Everything burned inside him. If the world meant to take his brother, it would have to rip him away by force.

Two days earlier, Genya had insisted on joining him for a mission. “Just reconnaissance,” he’d said. Idiot. Sanemi had relented, thinking it would be easy. Now he held him half-dead in his arms.

“Kocho!” His voice exploded, hoarse and torn, more roar than word. Not a command. Not a plea. Desperation made sound. “Help him!”

Shinobu appeared in the hallway, eyes wide, startled. She looked at him only for an instant, and that was enough. He followed without thought, teeth clenched, heart pounding like a hammer. The treatment room reeked of alcohol, flowers, and restrained death.

He laid Genya down on the cot with clumsy care. Then stood there, fists closed, still feeling the boy’s weight on his arms. As if letting go meant losing him.

Shinobu’s voice sliced through the air like a cold blade. “Surgery.” Precise words, measured, cutting the threat into manageable pieces. Nothing that sounded impossible — that’s what she had said once too. But the image of Genya dangling from his arms wouldn’t leave his head.

Sanemi’s chest constricted until it hurt. Blood glued to his fingers; sweat slid down his temple; a tremor shuddered beneath his jaw. A silent roar gathered in his chest, pushing, clawing to break free. Anger. Fear. Desperation. Short, animal thoughts. Everything tangled.

Everything too close.

Too real.

“He stays here.” His voice came out ragged, harsh, like metal twisting. He planted himself beside the cot, feet rooted to the floor. “I’m not leaving until he’s out of danger.”

She nodded, without argument. There was nothing to argue. But in her eyes flickered something he couldn’t name: alarm. Caution. Maybe both. Shinobu spoke again, her voice steady, calm with the practiced patience of someone who heals without haste.

“There’s no problem, Shinazugawa-san. You can use the guest room at the end of the hall — number three. It’s the quietest.”

Sanemi didn’t answer. He sank into a chair beside the cot and stared. Stared as if his gaze alone could hold his brother’s life together. Hours bled away, one after another, like blood spreading across a floor.

Night fell over the Mansion like dense ink. He was still there — tense as a bowstring, every nerve on edge, his pheromones hanging in the air, a blade suspended mid-slash. Anguish seeped into his bones; he wanted to tear the night apart with his teeth, destroy it until he found the root of the threat. Helplessness ate at him. Poisoned him.

Then something changed in the corridor. A shift. A thread of air crossing his own — so faint he almost dismissed it.

A scent. Different. Sweet. Damp. Like ripe plums left in the sun, like fresh water filtered through stone.

He froze.

Frowned. Drew in another breath.

No. It couldn’t be.

His mind reached for logic — Kocho’s herbs, camellia extract for treatment, another patient’s Omega trace. Excuses. Rationalizations. But his body didn’t wait. His stomach dropped. His throat tightened with a pulse he couldn’t master — a strange heartbeat, a chill creeping up his neck — and something inside him, uselessly proud, shrank for just a moment.