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Izuku was sick, or at least that’s the impression everyone was under.
He was actually in heat, which, while typical for his age, wasn’t presenting as a typical heat.
Even with his designation as an omega the milky scent of pup clung to him heavily where as his peers were growing into their matured scents.
He usually got away with just wearing scent blockers but his heat was making his scent strengthen, leaking through for anyone to smell just how different he was...how wrong.
Pup heats were different from mature heats, waves of blistering fevers still, but instead of intimacy of a sexual sort, his urge was to seek out affection and cuddles, something he was lacking due to the secrecy of his true designation.
He yearned more than anything for the embrace of warm arms and comfort, a dream that wouldn’t come to fruition.
Even at home before the dorms, his pup heats had been dealt with quite… clinically. His mom locked him in his room, bringing two meals a day and a jug of water refilled in case it emptied as his omega tried to nest but failed without any proper guidance, his only comfort being an old all-might plushie he still had propped on his bed.
His mother didn’t intend to be cruel, he thought, he was sure she was just misinformed; she was a beta after all.
He whined softly to himself, curled up in a feverish lump on his mattress, a sad ring of blankets around him in a very depressing impression of a nest.
He had tried looking up YouTube tutorials on how to make one, but it hadn’t seemed to click for him. What he really wanted was to curl up in a parent's nest and let them worry about everything that felt too big.
Izuku startled slightly looking up hazily from his bed at the door where a knock echoed out. Which was weird considering school was still in session.
“Midoriya? Kid, you alright, you decent? Because I’m coming in,” His homeroom teacher's voice prodded.
Well, that explains why someone was available to check on him. It should be foundational heroics right about now giving Aizawa Sensei a free period.
Izuku was equal parts anxious and thrilled that his Sensei was here. The more rational part was upset that he smelled so much like a puppy and was about to be discovered, and the puppy part was thrilled that an adult omega would be near to protect him while he was vulnerable.
Aizawa was personally steeling himself for the scarring things he might see if the kid was in heat. Midoriya did not have a good track record when it came to ‘just being a little under the weather, Sensei, I swear!’.
He thankfully hadn’t had to deal with any of his students going through a heat yet, seeing as Midoriya was the only omega in his class this year.
He heard panicked shuffles as he unlocked the door, peeking in. Heart breaking at the sight before him. Midoriya was sitting in a circle of ratty blankets in what he thought was supposed to be a nest, an iron grip on a frankly disgusting plushie donning all-mights faded smile.
The kid was a wreck with hazy eyes and flushed skin, and the acrid scent of a scared pup blasting him in the face the moment he opened the door. He didn’t know fifteen year olds could still smell so strongly of pup but his nose never lied, if Izuku’s scent was giving out pup he was a pup.
He crooned out, peeling off his scent patch and letting out pheromones of calm, calm, safe, safe as he hesitantly approached the pup's makeshift nest.
Heat-glazed eyes watched him with a mix of fear and need. He held out his wrist to the pup, asking silent permission to enter his 'nest'. Izuku sniffed at his wrist contemplatively before letting out stuttered chirps, an obviously out-of-practice vocalization for the kid, but one that screamed ‘I’m a baby, protect me’.
Pups were biologically different, it was a vocalization only they could make. This confirmed what Shouta already knew to be true, that Izuku Midoriya wasn’t just an anxious omega; he was a neglected omega pup.
He shuffled Izuku towards him, his inner omega cooing as the kid's exhausted form slumped into him, finally resting a bit now that someone was there to protect him. It made Shouta feel a little sick that the pup was reacting that strongly to having pheromones used on him.
Pushing aside his worry, he ran a hand through sweat-soaked curls, purring soothingly.
The pup wasn’t safe here, pup needed a nest, a real nest, his hindbrain whispered out now that a puppy was curled up on him.
He needed to protect this kid, and it would be so much easier if he could do it from the comfort of his own nest, but that brought up the issue of his other, admittedly more grown-up pup, Hitoshi, and his alpha Zashi.
He was mostly sure they wouldn’t mind, and it was his nest after all, but this wasn’t just about lending a puppy in need his nest. This was almost definitely going to turn into a new member-of-the-pack type thing. They, of course, would have to sever ties with Izuku’s previous negligent pack, but that would be easy enough with multiple intense scenting sessions.
But come to think of it, in the way of scents, Izuku was oddly void of any but his own, something strange for an omega, especially a puppy. It felt wrong for a kid to be this isolated, so disconnected from so many biological comforts.
Things were going to change for Izuku, regardless of his being a part of Shouta’s particular pack anyway; he only wished they could have known sooner that they were treating the pup like he was a grown omega when he was so obviously just a baby.
No wonder the kid was an anxious mess; he’s been completely neglected. Puppies need lots of affection, regular scenting, and specialized diets, especially when they are as tiny as Izuku.
An omega, Izuku’s age, should be going through a big growth spurt in preparation for becoming a mature omega. And although Izuku wasn’t on track for that development, his body should at least be trying to get a little bigger, regardless, he was fifteen!
He knows… that what is about to happen is going to scare the little omega but it’s for his own good, he’s played at being a big kid long enough. Once he submits to his puppy instincts instead of trying to hide them he’ll feel much better.
Aizawa glanced at the pup in silent contemplation as he texted his husband about the situation, being met with sympathies and worried texts about the little listener.
His alpha was so perfect, worrying about the pup like that.
Next, he messaged recovery girl to meet him at his apartment for a check-up on the green-haired omega. And finally, he gave Hitoshi a rundown slightly amused at his son's shock at his crazy strong classmate actually just being a little puppy.
Scooping up the pup, he ran them to his on-campus apartment, taking great care to avoid any students and staff as Izuku dozed lightly, scent drunk from being exposed to Aizawa’s strong pheromones, having little experience with how to resist them.
“Ah, Chiyo, you’re already here, good. I’ve settled him, but I find it concerning how easy it was to get him scent drunk like this. Signs of neglect for sure. I found him in heat, and I’m sure you’ve smelled it by now; he has pup written all over him.” Aizawa broke it down for the elderly hero as he placed Izuku on his sofa, Chiyo’s makeshift check-up station already set up.
“Very peculiar, Aizawa, and yes, very concerning, there would be very few reasons for an omega of Midoriya’s age to stay a puppy that weren’t heartbreakingly awful. But from what you’ve said about his pheromone sensitivity, I’m inclined to believe it’s neglect as well.” Recovery girl said with a sad but thoughtful look on her face.
“I’m going to test how stunted his biological development is to give you a good plan for his care, I’m thinking pretty young based on his scent alone.” She informed as she walked over to the pup, medicine bag in hand.
He watched in distress as Chiyo pricked the little one’s finger, dripping it onto a scanner that, with a mechanical whir, projected a hologram full of Izuku’s hormone levels.
“Hmmm… he has the hormone levels of a very young pup, about a three to five-year-old pup to be specific. It is appalling that no one noticed before now, especially a doctor. But given the suspected neglect and his locked records, we might be able to assume he hasn’t been to a doctor in a while.” Chiyo observed.
She did a few more tests, Izuku frowning all the while.
“What’s the verdict?” Aizawa sighed, comforting Izuku by pushing the boy into his neck, letting his scent drip out as the boy went limp, barely aware of the world around him.
“Well, besides being a young pup, hormone-wise wise he’s also quite underweight and will be prone to scent sickness if he isn’t regularly scented now that he will be having consistent interaction with it. I think with a severe case like this, we should put him on some omega formula just until he’s at a healthy weight… Honestly Aizawa, just treat him like what he is. A puppy. He might fight at first because of him being in a constant fight for survival and independence but he will settle eventually.” She explained calling a med bot to deliver some pup related items.
“Thank you so much for the help, really it’s nice to know this kid has some people in his corner,” Aizawa said looking softly down at the bundle of green hair hiding in his neck, soft puffs of air hitting the skin.
“Of course, and Aizawa I know you’ve probably already come to the same conclusion, but he can not stay in the hero course at least as long as his development is stunted and he’s a pup like this,” she said, a sorrowful look in her eyes, she knew it was for the best for the time being but it was still hard to come to terms with.
“I know.” He said a sullen look on his own face, the kid was going to be devastated.
It was truly for his own good, the pup had shown he wasn’t ready, there were signs even before the reveal of his little secret.
Images of broken bones and poor quirk control flashed through his head as he fought down guilt.
He heard the front door click shut at the exit of RG and sagged a bit, Izuku firmly in his arms.
Nest, nest, the baby needs a nest. Aizawa’s omega instincts flooded his brain now that he was back in his den with no outsiders.
Racing to the bedroom, he set Izuku in the middle of the nest. A giant ornate twist of soft blankets intertwined with scented cloths. Cushy pillows were scattered around the edge of the nest in an arch, whilst the bottom of the nest was made of expensive nesting pillows covered in multiple duvets. There were obvious touches of his pack in the mound of soft items like a purple cat plushie of Hitoshi’s and a leather jacket of Mics, Nemuri’s blue sweater she liked to wear, and that he refused to give back.
The scents of home saturated the nest in a comforting way.
The overall nests main color was a deep purple that Izuku seemed to stick out from with his pale skin and green curls. Aizawa let out a content purr as the puppy nuzzled into the nest the scent he now knew to be Izuku’s milk and cinnamon bleeding into the pillows.
He watched the puppy doze for a bit longer, stilling when he felt a presence next to him.
Hizashi eyed the puppy in the nest, and then his omega; they had to talk.
———
Izuku woke up with a start.
He remembered, under the haze, vague memories of gentle prodding, Recovery Girl's whispered voice, and the sensation of finally letting go: slipping up. But with those memories came the panic of his discovery.
If Recovery Girl had been in the glimpses of his memory, that meant this wasn’t going to be a quiet ordeal; it meant it was going to be serious conversations and interrogations on why Izuku is the way he is. His breath picked up as he looked around the unfamiliar nest he was in.
“Izuku, baby, calm down.” Aizawa’s worried voice cut through the silence, clambering into the nest with him to soothe him.
“No sensei, no. Not supposed to be here, please. I’ll go back to the dorm, sorry for bothering you.” Izuku whimpered out.
Aizawa shot him an odd look as he called for an unfamiliar figure to enter the room.
“Mic Sensei?? What are you doing here…” Midoriya questioned, head tilted in confusion. He sniffed the air, picking up the usually hidden scents of his teachers, the ones he now recognized as also being the ones in the nest… oh, they’re mates.
“Oh my, I’m in your nest. I’m sorry!” He yelped
Hizashi looked over tinted glasses at his mate and the pup with sad eyes, mentally preparing himself to be stern with the puppy, thoughts of Aizawa’s and his earlier conversation milling about.
Aizawa said the puppy didn’t know how to be a puppy, they would have to be stern to teach him.
Leave no room for argument.
“Settle down, puppy, your Dam put you right where you belong: in his nest. You need to rest, little one, you’re in heat.” Yamada scolded, keeping his scent light so he wouldn’t scare the pup.
Izuku whimpered, neck bared at the alpha's tone, head stuffed full of confusion and anxiety.
He just wanted to know what was going on! And now everyone was treating him like a baby. He was fine! He could go back to his dorm and wait this whole thing out. But now he had to think of a way to escape his teacher's watchful eyes, especially with his revealed puppy designation.
“NO! I want to go back to the dorms now! It’s not fair I didn’t ask to come here.. and-“ Izuku was cut off from continuing as the surprisingly large hand of his English teacher scruffed him. His eyes went wide as his body went completely limp. Sagging uselessly as he whined.
“We know you’re stressed, little one, but that is no excuse to speak to your Sire and Dam that way! Say sorry to Mama, puppy, at once.” Mic growled.
Aizawa observed quietly as Izuku’s puppy finally showed itself for a fleeting moment, baring its neck and chirping in apology.
“Izuku is so sorry, Mama,” he whispered, teary eyes looking up at Shouta.
“I think we need to talk kid,” Aizawa said in reply eyes softening at the sad freckled face of his pup.
Now collected on the couch, Aizawa started with the questioning.
“Why didn’t you tell us, kid, you’re smart, you know that being a puppy and a hero just isn’t realistic.
Look at how you reacted when Papa scruffed you earlier; that could get you killed, along with your sensitivity to scents. I’m not sure how much you remember, but you get scent drunk really easily, kid, that’s okay for when we are at home, but on the field it’s a liability.” Aizawa lectured, a rational argument for Izuku’s part of himself that was still fighting the puppy instincts. Although Aizawa would much rather just tell the little boy that he had to listen to his Dam and have that be the end of it.
“But I can be a hero, please, Sensei. I know I can, you’re only acting like I can’t because you know I’m a dumb puppy. But I was doing great before! Please,” Izuku begged.
“Except for you weren’t little listener, from what I heard, you weren’t rockin’. I heard you had no nest, no one was scenting you, and everyone was letting you play big boy. You think it’s okay, but it isn’t Izuku. You didn’t question why you’re still a pup. It’s because all your needs were being neglected; the choice really isn’t yours, little listener, puppies don’t know what’s best for them. Dams and Sires do.” Hizashi interjected.
Izuku felt dread settle in his gut as he looked at their faces, coming to the realization that they were serious about the puppy thing; he was going to be stuck and treated like a baby unless he got out of there.
“So I… I can’t be a hero with my friends?” He questioned wanting a straight answer.
A look was shared by the adults.
“Not right now, kid, you’re out of 1-A for the time being,” Aizawa confessed.
Izuku wailed. Kicking his feet in a fit of rage, as Shouta and Hizashi tried to grab him, to hopefully calm him down.
But before they could he used black whip to launch himself across the room running for the door as the adults faltered. Aizawa failed to use his quirk as Izuku launched to the roofs out of sight.
It should be the end of foundational heroics, he should be able to find one of his friends to help.
Looking down, he spotted a swath of purple hair sighing in relief as he descended from the roof.
“Shinsou, help me! I need to get back to the dorm before Aizawa Sensei finds me!” He begged, forgetting his lack of scent patches as the smell of a distressed puppy filled the air.
Tired lavender eyes locked onto him in surprise before they steeled over. Shinsou went to reply when a small cluster of 1-A students rounded the corner at the scent of a pup.
“Who has a puppy on campus, I didn’t think Eri was going to be here today??” Uraraka exclaimed stilling along with Iida, Kirishima, and Denki as they finally laid eyes on exactly where the puppy scent was coming from.
“Is that Midobro? Why does he smell like a pup?” Kirishima exclaimed, wrinkling his nose at the scared pheromones leaking out of the kid.
“A better question is, where is his Dam? he’s in heat. It would be the responsible thing to leave him be while the situation is sorted.” Iida directed, promptly being ignored as Denki bounded over to Izuku.
“Woah, he sure is a puppy he has the exact smell and everything, I can’t believe he flew under the radar this whole time!” Denki exclaimed, though he looked apologetic at Midoriya’s scared look.
“Guys, it’s still me! Please, I need to get to the dorms. He’s looking for me!” Midoriya begged, stomping his foot in frustration.
“Ah I see what’s going on, someone made their Dam mad and is trying to hide. Settle down, you’ll see your Dam soon. And on behalf of class 1-A, we apologize for treating you the way we have Izuku, how completely inappropriate of us we will endeavor to treat you as your designation suggests in the future. We weren’t aware of your designation, please forgive us.” Iida said bowing deeply.
Midoriya spluttered in frustration, turning a bright red as Uraraka and the others cooed at him.
Hitoshi kept an eye on the interaction as he texted their Dam their location feeling pity for the confused little puppy.
“Izuku Midoriya, you get over here right now.” Aizawa’s voice boomed out, capture weapon shooting out to snag the pup.
The 1-A students smelled the bitter scent of furious, protective, worried Omega and smartly decided to leave the green-haired boy to face his Mama.
Hizashi ran up, not far behind, growling at the kids unlucky enough to be walking by.
“Thank you for messaging Flower, sorry about your new little brother, he’s having trouble adjusting,” Hizashi whispered to his purple-haired son. Standing off to the side as they watch Midoriya squirm in his bindings.
“You weren’t listening to me!” Izuku sniffled overwhelmed with the scent coming off Aizawa.
Izuku didn’t understand why his not wearing scent patches was affecting how everyone treated him. He still has a puppy smell but so what?
“Little boy, we are going home and you’re having a conversation with Zashi’s hand, then we’re going to show you how much of a puppy you really are and you aren’t leaving my nest for a week.” Aizawa barked out voice full of anger.
Izuku sobbed in embarrassment as he was dragged back to his Sensei's apartment, giving Shinsou a pathetic, teary-eyed look as the purple-haired boy headed to the dorms, sparing a glance and wincing in sympathy.
“Come here, sweetheart, things are just so new and scary, huh?” Hizashi said as Shouta dropped the kid on the couch next to him, gruffly sitting in the armchair across from
Izuku looked up at Hizashi, nodding sadly, lower lip jutted out.
“And we understand that, sweetheart, but running away from Mama and Papa is a no-no.
You’re a pup in heat with a very powerful quirk. You could get hurt, honey. So Mama and I are just going to have to get that message through and make sure you don’t want to run again.
Because even if you don’t get hurt out there miraculously, you’ll get a spanking in here for putting yourself at risk.” Hizashi explained to the baby, their hearts hurting when he squirmed away.
Izuku yelped as he was placed over Papa's lap, noticing Ma-Aizawa shuffling to the kitchen out of the corner of his eye.
“Ten, honey, then it’s over,” Hizashi stated, scruffing Izuku gently when he tensed, feeling the kid relax over his lap, he began.
Two in rapid succession as the puppy whined that cinnamon milk scent strengthening. Four more as little legs kicked out in retaliation. And the final four delivered with a firm palm enough to sting for maybe an hour, all done over the kid's pants, of course.
A punishment a teenager would be embarrassed by, but a puppy would be devastated, which was proven by the stuttered sobs coming from the kid as he was righted the right way up.
“Oh darling, Papa is so sorry he had to do that, but puppies need to listen to their Sires and Dams instead of pretending to be big boys.” Hizashi soothed wiping tears off of flushed, freckled cheeks, the kid's heat still giving him an odd warmth radiating off his skin.
Hizashi signaled at Shouta as he came in with the package Chiyo sent. He was sure Nezu had been a part of the care package when he saw the parenting books and puppy clothes and an honestly creepy Nezu plush that made him shudder.
Letting out soothing pheromones, he watched Izuku’s head loll into Hizashi’s shoulder, small sniffles escaping him still.
“Need to get puppy comfortable, hand him over,” Aizawa demanded, glaring at the amused look in Hizashi’s eyes that basically screamed ‘You’re a mother hen and I find that hilarious’.
Aizawa stripped Izuku down with minimal whining on the pup's part, putting him in appropriate wear.
Soft, breathable clothes, a nice blue sweater with a duck on it, and blue shorts with some white ankle socks. And as a precaution, quirk-canceling bracelets that made the kid screech for a moment before his head was placed in Shouta’s neck effectively silenced him when he inhaled at his scent gland.
Shouta cooed internally happy that the pup was being so well-behaved, although, upset at the defiance left in the green-haired boy's eyes.
Izuku felt lax and odd as he was subjected to the babying, instincts purring inside him, yelling at him to submit and relax. But he was big, he had to be big. Still that small part of him wanted to just curl up in a nest with a full belly snuggled into his Dam and Sire.
Izuku was dropped in the armchair, Aizawa, head leaning against the broad chest of his teacher, as a bottle was pulled out, warm and full of a sweet-scented liquid that had his mouth watering.
He was way too old for bottles, though, no matter what they said about him being a puppy.
“Come on Puppy drink up you’re far too skinny. Mama promises it’s yummy, give it a chance and then we can go lay in the nest.” Izuku frowned biting his lip in thought.. he really did want the comfort of the nest.
Today had been scary and new and all under the haze of his heat.
Aizawa sighed when he took too long pinching his nose until he opened his mouth to breathe, but instead was met with the nipple of the bottle.
He spluttered around it in surprise as he looked at Mama in betrayal. But long suppressed instincts began to show as he chirped as he ate, surprising himself as he took frantic, starved sips.
Aizawa and Hizashi looked at the starved baby in sadness, watching him finally give in after so long was satisfying, but made the signs of neglect all the more obvious. Needy sips of nutrients he so badly needed and had been missing.
As he finished his bottle, his eyes finally settled, completely hazed over in a way that could only mean he had given in, fully embraced his inner puppy.
Further proven as they headed for the nest,
“Mama, nest please n' I want Papa too. Don’t feel good, Mama.” Izuku frowned, fever still working its way through him, though starting to cool down now that his inner puppy knew he was protected.
“It’s okay, baby Mama and Papa will hold you, you just relax, sweet thing, you’ve earned it,” Aizawa whispered into fluffy curls.
The group settled in the nest Izuku wrapped around his worn all-might plush sandwiched between his parents completely relaxed for the first time in a very long time. No pressure to save the world, no pressure to act like a beta for Inko. Just the expectation to relax because his Dam said so.
He chirped in contentment, finally safe to fall asleep, his Papa and Mama would protect him.