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Aizawa got home from patrol, ready to collapse straight into bed and sleep for the next couple of days. Patrol had been routine—just breaking up a few fights in alleyways—and he wanted nothing more than for this routine day to continue.
He left his capture weapon, goggles, and utility belt by the doorway, not bothering to put them away, and headed straight for the couch, tossing out an "I'm home" to let Izuku, who should have been there, know he'd arrived.
He didn't get a response. It wasn't unlikely that Izuku simply hadn't heard him, but something told Aizawa that things were wrong—very, very wrong. The apartment was too quiet, and the air felt heavy in a way that promised nothing good. Call it a sixth sense, call it a hero's intuition, but he felt the unease settle over him.
"Izuku, are you home?" he called again, moving through the living room, past the abandoned backpack slumped against the coffee table, papers and markers scattered across the surface, the laptop's screen dimmed with its saver. He went down the hallway toward his kid's room. The door was ajar, the light on, and—
Aizawa's heart dropped to the pit of his stomach at the glimpse of green hair through the narrow gap in the door. He shoved it open and dropped to his knees beside Izuku's unconscious body on the floor.
Izuku was crumpled beside his desk, one arm stretched out, the other curled against his chest. His skin had gone ashy pale, almost ghostly white, with a faint bluish tint darkening his lips and the beds of his nails. His face was slick with a cold sweat, curls damp against his forehead, his shirt clinging to his skin.
"Izuku, kid, can you hear me?" Aizawa cupped his cheeks with rough hands, tapping lightly, trying to pull a response out of him.
Nothing.
He checked him methodically, the way his training had drilled into him a hundred times over. Izuku's pulse fluttered weak and thready under his fingers, stuttering unevenly, skipping beats, lurching between too fast and frighteningly slow. His breathing came shallow and ragged, ragged little pulls of air punctuated by the occasional gasp. His hands, when Aizawa gripped them, were ice-cold—far colder than they should have been, colder than the room around them.
No visible injuries. No blood. No dislocated limbs. No forced entry into the apartment. None of it made sense.
His mind raced through possibilities—quirk accident, poison, villain attack—what, what, what—but there was nothing. No sign of a struggle, no evidence of anything except Izuku, unconscious and fading in front of him, and Aizawa had no idea why.
"Okay. Okay, first things first," he told himself, keeping an iron grip on his own terror. An ambulance would take ten minutes to arrive, but he could get Izuku to the hospital in that same amount of time if he drove himself—except then he wouldn't be able to monitor him on the way. The calculation took less than a second before he grabbed his phone. "This is Eraserhead. I need an ambulance at—"
-----------------------
The hospital waiting room wasn't crowded, just a family and a couple of individuals scattered in the far corners, and it smelled like antiseptic and bad coffee, though neither had anything to do with the way Aizawa's stomach twisting, nor the burn in his chest.
He didn't understand. He had no idea what had happened to Izuku, and he was sitting there, useless, without a single piece of information about his kid's condition. Keeping him safe had been his only responsibility, and he felt like he'd failed at it completely.
The scene kept replaying in his head, over and over. Nothing had been out of place. Nothing had been unusual. What had he missed?
"Mr. Aizawa?"
He was on his feet before the doctor finished saying his name.
"He's stable," the doctor said first, and Aizawa's knees nearly buckled with relief. "We've run a full workup—no head trauma, no toxins, no underlying cardiac abnormalities that we can detect."
"Then what happened?"
The doctor's expression shifted into something uncomfortable and pitying all at once. "We believe it was takotsubo cardiomyopathy. Broken heart syndrome."
The words didn't make sense. Aizawa stared at him.
"It's a stress-induced cardiomyopathy," the doctor continued. "The heart's left ventricle temporarily weakens due to a surge of stress hormones. It mimics a heart attack, but there's no arterial blockage. It's usually triggered by severe emotional distress—grief, shock, overwhelming fear."
Aizawa's mind went blank. What could have happened that day to trigger something like that? "What—what could have caused that? Did something happen to him?"
"We were hoping you might know," the doctor said gently. "Did he receive any traumatic news today? Experience a loss? Extreme stress?"
"I don't—" Aizawa's hand came up to rake through his hair, tugging slightly. "I was at work. He was fine this morning. I don't know what—"
"It's alright. He's stable now, and the condition is usually reversible with rest and monitoring. We'll keep him overnight for observation. You can see him—he's starting to wake up."
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Izuku looked impossibly small in the hospital bed, tucked under thin white sheets with an IV line taped to his inner elbow. His eyes were open but unfocused, staring somewhere past Aizawa's shoulder at nothing.
"Hey," Aizawa said softly as he crossed the room and pulled the visitor's chair right up against the bed. "Izuku. Can you hear me?"
Izuku's eyes tracked slowly toward him, but there was something distant in them, as if he wasn't entirely anchored to the same reality as Aizawa. Something hollow.
"You're in the hospital," Aizawa continued, keeping his voice calm and even. "I found you unconscious at home. The doctors say you're going to be okay." He reached out carefully, resting a hand on Izuku's shoulder. "Can you tell me what happened?"
Izuku blinked slowly. Didn't answer.
Aizawa's chest tightened. He moved his hand from Izuku's shoulder to the back of his head, fingers threading gently into his curls, trying to ground him. "Hey. You're safe. You're okay." He applied gentle pressure. "I've got you."
But Izuku didn't lean into the touch the way he always did. He didn't react at all, really—just kept staring with that glassy, thousand-yard expression.
"Kid, I need you to talk to me," Aizawa said, failing to keep the worry out of his voice. "What happened? Did someone hurt you? Did something scare you?"
Silence.
Aizawa pulled him carefully into a hug, mindful of the IV and the monitor leads, wrapping both arms around him and cradling the back of his head. "It's okay," he murmured. "Whatever it is, it's okay. Just breathe."
Izuku sat rigid in his arms—not fighting, not pulling away, but not there either. Like he was somewhere else entirely.
"Izuku, please—"
"When do I leave?"
The words were so quiet Aizawa almost missed them.
He pulled back, hands moving to frame Izuku's face so he could look at him properly. "What?"
Izuku's eyes finally focused on him, and they were devastated—Izuku looked at him like he'd ripped his heart out and stepped on it. "When do I have to leave? How long do I have?"
"Leave?" Aizawa's mind scrambled for context. Was Izuku upset about being in the hospital? He knew it wasn't anyone's favorite place, but that wasn't how Izuku had ever reacted to it before. "Izuku, you're not—the hospital is keeping you overnight for observation, but then you're coming home. You'll be discharged tomorrow if—"
"Not the hospital." Izuku's voice was flat. Resigned. "Your apartment. When do I have to go back?"
Aizawa's blood ran cold. "What are you talking about? You're not going anywhere. You live with me."
"I saw the paper."
"What paper?"
"The one in your desk." Izuku's breath hitched, but his expression stayed eerily blank. "The placement evaluation. I didn't mean to look—I was just trying to find tape for my poster, and the drawer was open, and I saw it, and—" His voice cracked. "I know you're giving me up. I just want to know when. So I can—so I can prepare."
Understanding hit Aizawa like a freight train.
The routine paperwork. The form the fostering system sent every month as a matter of policy—the one he'd filed away three days ago without a second thought, because it meant nothing, because it was just a time-consuming piece of bureaucratic box-checking. Izuku had found it and thought it meant something else entirely.
"Oh my god," Aizawa breathed. "Izuku, no. No, that's not—" He tightened his grip on Izuku's face, making sure the kid couldn't look away. "That form doesn't mean I'm giving you up. It's routine. The agency sends it automatically every month to check in. It doesn't mean anything is changing."
Izuku stared at him like he was speaking a foreign language.
"You're not going anywhere," Aizawa said, slow and deliberate. "I'm not sending you back. That paper was just—it's bureaucracy. Red tape. It doesn't mean anything except that I have to confirm you're still living here, which you are, because this is your home."
"But it said evaluation—"
"Standard procedure. They evaluate every placement regularly. It doesn't mean there's a problem." Aizawa moved one hand to the back of Izuku's neck, thumb stroking gently at the base of his skull. "I should have told you about it. I should have explained how the system works. I didn't realize—" His voice caught. "I didn't realize you were still waiting for this to end."
Izuku's breath shuddered.
"Is that what happened?" Aizawa asked quietly. "You saw that form and thought I was sending you away?"
Izuku nodded, and something in his face finally cracked. "I couldn't breathe," he whispered. "I saw it, and everything went—everything felt wrong, and I couldn't—my chest hurt, and I thought I was going to throw up, and then everything went black."
"Your heart gave out from the stress," Aizawa said, and his own chest felt tight just saying it. "The doctors called it broken heart syndrome. Your body couldn't handle the fear."
Izuku's eyes went wide.
"So let me be extremely clear," Aizawa continued, both hands still cradling Izuku's head, grounding him. "You are not leaving. You are my kid. I'm not giving you up, I'm not sending you back, and that's not going to change. Do you understand me?"
"But what if I mess up—"
"You won't mess up badly enough for that. There's no mess-up big enough for that. You're stuck with me. Okay?"
Izuku made a sound like something breaking, and suddenly he was sobbing—huge, wrenching gasps that shook his whole body. He collapsed forward into Aizawa's chest, hands fisting desperately in his shirt.
"I thought—I thought—"
"I know." Aizawa wrapped his arms around him properly now, one hand stroking through his hair, the other firm and grounding against his back. "I know. I'm so sorry you thought that. I'm sorry I didn't explain."
"I was so scared—"
"I know, kid. I know." He rocked him slightly, instinctive and gentle. "But you're safe. You're staying. We're both staying."
Izuku sobbed harder, face pressed into Aizawa's shoulder, and Aizawa just held him through it, let him cry out weeks or months of terror he'd apparently been carrying alone.
"I've got you," Aizawa murmured into his hair. "You're safe. You're mine. You're not going anywhere."
It took a long time for the crying to slow. When it finally did, Izuku stayed curled against Aizawa's chest, exhausted and wrung-out.
"You scared the hell out of me," Aizawa admitted quietly, still stroking his hair. "I came home and found you on the floor, and I didn't know what happened. I thought—" His voice caught. "I thought I was going to lose you."
Izuku's hands tightened in his shirt.
"So no more assuming the worst and letting it break your heart, yeah?" He said it gently, pulling back just enough to look at Izuku's face. "If something scares you that badly, you come to me. You ask. Even if you think you already know the answer. Especially if you think you already know the answer."
"Okay," Izuku whispered.
Aizawa wiped a thumb across his cheek, clearing away the tear tracks. "Good."
He glanced at the narrow hospital bed, then at Izuku's exhausted, red-rimmed eyes, and made a decision. Carefully, he maneuvered himself onto the bed beside Izuku, sliding one arm under his shoulders to pull him close against his side. The bed was barely big enough for one person, let alone two, but Aizawa didn't care. He tucked Izuku's head under his chin, wrapped his other arm around him, and felt the kid finally, finally melt into the embrace.
"There," Aizawa murmured, pressing a kiss to the top of Izuku's head. "That's better."
Izuku made a small, broken sound and burrowed closer, one hand fisting in Aizawa's shirt while the other clutched at his arm.
"I've got you," Aizawa said softly, running his fingers through Izuku's hair in long, soothing strokes. "You're safe. You're right here with me, and I'm not letting go."
"Promise?" Izuku's voice was barely audible.
"Promise." Aizawa tightened his hold. "Sleep now. I'll be right here when you wake up."
Izuku's breathing gradually evened out, his grip loosening as sleep pulled him under. But even unconscious, he stayed pressed close, as if he needed the contact to believe it was real.
Aizawa stayed awake, one hand never stopping its gentle path through Izuku's curls, the other arm wrapped secure around his shoulders. The monitors beeped steadily. The IV dripped. And Aizawa held his kid close, making silent promises to be clearer, to check in more, to make sure Izuku never had to carry that kind of fear alone again.
Outside the window, the sun set over Musutafu. Inside the hospital room, wrapped safe in his father's arms, Izuku slept without nightmares for the first time in weeks.
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The first few days after the hospital were different.
Izuku noticed it immediately, though he didn't quite know what to do with it.
Aizawa had always been physically affectionate in his own quiet way—a hand on the shoulder, fingers ruffling through hair, the occasional side-hug. But this was something else entirely.
Now, every time they sat together, Aizawa pulled him close.
It started the moment they got home from the hospital. Aizawa guided him to the couch with a gentle hand on his back, then settled beside him and immediately tucked Izuku against his side, arm wrapped around his shoulders.
"You're supposed to be resting," Aizawa said, his voice softer than usual. Almost careful. "Doctor's orders."
Izuku nodded mutely, still processing the fact that Aizawa's hand was stroking slow, repetitive, grounding patterns against his upper arm. It never stopped that night.
Movie night that Friday found Izuku curled up against Aizawa's side on the couch, tucked under a blanket with Aizawa's arm around him and his fingers carding gently through Izuku's hair.
"This okay?" Aizawa asked quietly, and Izuku nodded, his throat too tight to speak.
It was more than okay. It was everything he'd ever wished for.
Doing homework at the kitchen table while Aizawa graded papers across from him was ordinary enough, except for Aizawa offering him one of his favorite snacks every now and then, and ruffling his hair whenever he passed behind Izuku's chair, his hand lingering a beat longer than necessary.
Breakfast was the same. Dinner was the same. Any time they were in the same room and sitting down, Aizawa found a way to be close—an arm around Izuku's shoulders, a hand in his hair or resting at the back of his neck. And his voice had changed too. Softer, like Izuku was something fragile that might break if handled too roughly.
"Hey, kid. How was school?"
"You doing okay? Need anything?"
"Come sit with me for a bit."
Never demanding. Never pushy. Just there. Constant and gentle and safe.
But the biggest change came at bedtime.
Before the hospital, Aizawa's routine had been simple: stick his head in Izuku's doorway, ruffle his hair, say goodnight, and leave. Quick and easy and comfortable in its predictability.
Now, Aizawa came into his room properly. He sat on the edge of the bed while Izuku settled under the covers, then pulled the blanket up to his shoulders with careful hands.
The first night, Izuku had watched with wide eyes as Aizawa tucked him in like he was something precious.
"Comfortable?" Aizawa had asked softly.
Izuku had nodded, unable to find words.
Then Aizawa leaned down and pressed a kiss to his forehead—gentle and deliberate and real—before smoothing his hair back from his face.
"Sleep well, kid," he'd murmured. "I'm right down the hall if you need me."
Izuku had lain there in the dark long after Aizawa left, hands clutching the blanket tight, as if letting go would make all of it disappear, trying not to cry.
It happened every night after that.
Aizawa would appear in his doorway around nine-thirty, sometimes still in his teaching clothes, sometimes already changed into worn sweats. He'd cross the room and sit on the edge of the bed, waiting while Izuku put down whatever book or phone he'd been looking at.
"Ready for sleep?" he'd ask, his voice always low and gentle. Izuku would nod and slide down under the covers, and Aizawa would pull them up around his shoulders, making sure he was warm and settled.
Then came the kiss—to his forehead or the top of his head, always accompanied by a hand smoothing through his hair.
"Goodnight, Izuku."
"Goodnight, Aizawa-san."
Sometimes Aizawa lingered a moment, fingers carding gently through his curls. Sometimes he squeezed Izuku's shoulder. Sometimes he simply looked at him with an expression Izuku couldn't quite name, but that made his chest feel warm and tight all at once. Then he'd leave, and Izuku would lie there in the dark, feeling safer than he'd ever felt in his entire life.
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It was Tuesday evening, almost a week after the hospital, when Izuku finally found the courage to ask.
They were on the couch again—Aizawa's default spot lately, always with room beside him for Izuku to tuck into. Izuku was curled against his side, Aizawa's arm around his shoulders and hand resting in his hair, the TV playing something neither of them was really watching.
"Aizawa-san?"
"Mm?" The hand in his hair didn't stop its gentle movement.
"Why are you..." Izuku trailed off, not sure how to finish the question without sounding ungrateful. "You've been really... um..."
"Clingy?" Aizawa supplied, a hint of dry amusement in his voice.
Izuku flushed. "I wasn't going to say that."
"It's accurate." Aizawa's fingers traced a gentle path from his temple to the nape of his neck. "You scared me, kid. Badly. And I realized I haven't been clear enough about..." He paused, as if choosing his words carefully. "About how much I want you here. How permanent this is."
Izuku's breath caught.
"So I'm making it clearer," Aizawa continued, softer now. "If you need me to back off, tell me. But if you don't..." His arm tightened slightly around Izuku's shoulders. "I'm going to keep reminding you that you're safe here. That you're wanted. That this is real."
"I don't—" Izuku's voice cracked. "I don't want you to back off."
"Good." Aizawa pressed a kiss to the top of his head, easy and natural. "Then come here."
He shifted, pulling Izuku more fully into his side, and Izuku went willingly, tucking his head under Aizawa's chin and letting himself be held.
"You're my kid," Aizawa murmured into his hair. "And I'm going to make sure you never forget that again."
Izuku's hands fisted in Aizawa's shirt, holding on tight, and for the first time since waking up in that hospital bed, he let himself believe it might actually be true.
They stayed like that for a long time—Izuku wrapped safe in Aizawa's arms, one hand stroking gentle patterns through his hair, the other firm and grounding against his back. And slowly, carefully, something deep in Izuku's chest began to unknot.
That night, when Aizawa came to tuck him in, Izuku was already under the covers, waiting.
Aizawa sat on the edge of the bed like always, smoothing the blanket over Izuku's shoulders. But before he could lean down for the goodnight kiss, Izuku spoke.
"Thank you," he said quietly. "For... for all of this. For making sure I know."
Aizawa's expression softened. He cupped the side of Izuku's face with one hand, thumb brushing gently across his cheekbone.
"You don't have to thank me for this," he said. "This is what parents do."
Izuku's breath hitched.
Aizawa leaned down and pressed a kiss to his forehead, lingering just a moment longer than usual. "Goodnight, kid," he murmured against his skin. "I love you."
The words were so quiet Izuku almost missed them. Almost.
But they landed like an anchor, solid and real and undeniable.
"I love you too, Dad," Izuku whispered, his voice cracking on it.
Aizawa went still.
For a second, he didn't move at all—didn't breathe, didn't blink, just stayed frozen with his hand still cupped against Izuku's cheek, like the words had physically knocked something loose in his chest. Izuku's eyes went wide, a flicker of panic crossing his face like he was already bracing to take it back, to apologize, to—
"Say that again," Aizawa said, low and rough.
Izuku swallowed. "I—Dad?" It came out smaller this time, uncertain, testing.
Something in Aizawa's face cracked open. He huffed out a breath that was almost a laugh, almost a sob, and pulled Izuku into a tight hug instead, one hand cradling the back of his head.
"Yeah," he breathed against his hair. "That's—yeah. I'm your dad."
He held on a moment longer than necessary, like he needed the contact to make it real.
"I'm your dad," he repeated, quieter now, almost to himself, like he was trying the words on and finding they fit perfectly.
Izuku's breath hitched, tears welling up again, but different this time—not fear, not grief, just overflow. "Dad," he said again, like he was allowed to now. Like it was safe.
"I've got you," Aizawa said, pulling back just enough to brush a thumb across his cheekbone, catching a tear before it could fall. "Always. You understand me? Always."
Izuku nodded, throat too tight to answer.
Aizawa glanced at the empty side of the bed, then back at Izuku's face, still blotchy and overwhelmed. He made a decision.
"Scoot over," he said.
Izuku blinked at him. "What?"
"You heard me." Aizawa was already toeing off his slippers, pulling back the blanket on the other side. "Scoot over."
Izuku scooted, wide-eyed, and Aizawa settled in beside him, pulling the blanket up over both of them. It wasn't the hospital bed—there was actually room to breathe here—but he still curled an arm around Izuku's shoulders and tucked him in against his side, the same way he had that night in the hospital.
"Dad?" Izuku said again, quieter, still testing how it felt in his mouth.
"Yeah, kid?"
"Nothing." Izuku pressed closer, a small, disbelieving smile tugging at his mouth. "Just wanted to say it again."
Aizawa's chest ached in the best possible way. He pressed a kiss to the top of Izuku's head and settled back against the pillow. "Say it as many times as you want," he murmured. "I'm not going anywhere."
Izuku's hand found the front of Aizawa's shirt, fisting loosely in the fabric—not desperate this time, just anchoring. Comfortable. Safe.
"Sleep now," Aizawa said, one hand resuming its slow path through Izuku's curls. "I'll be right here."
"You're staying?"
"All night." Aizawa's voice was steady, certain. "Where else would I be?"
Izuku's breathing evened out slowly, his grip loosening as sleep finally pulled him under, but he stayed curled close, tucked against his father's side.
Aizawa lay awake a while longer, one arm wrapped securely around his kid, listening to the quiet, even sound of his breathing. Steady. Safe. Real.
His kid. His son.