The pain began when he entered UA.
Of course when he first presented he had his moments, in which he had to come home after being bullied and mocked. He'd be on the verge of a drop, sometimes in the midst. He'd curl up in his mother's arms, surrounded by the scent of home until awareness returned and the gray at the edge of his vision disappeared. His mother was a beta but she did her best just to comb her fingers through his hair and reassure him, Ordering him to do small things like open his mouth for a bit of food and hold still while she groomed him. It was enough for him and if it wasn’t, well.
Sometimes, she wasn't home. Their rightful alpha had left, disgusted by having not only a quirkless son but an Omega for a son at that. And his mother worked so hard to make sure they survived and worried so much that he couldn't tell her how sometimes he wanted to scratch the skin off his arms, or how he couldn't keep meals down because he needed, no, he wanted to be held and praised before he could stomach it. Sometimes he dropped and it was scary...but he got through it. He learned to manage himself because his mother had too much to worry about. He could do this one thing to make life easier; he didn’t have to let his nature rule his life.
Afterall, how could he be a hero if he couldn't even keep himself from dropping after something as small as a bad day at school?
He found that he could sometimes keep it at bay by combing his own hair, by taking a bath with soothing scents, by watching a movie or listening to the same few songs over and over. If it got too bad he’d curl up in his mother’s bed, setting an alarm so he went back to his own room by the time she was off work. If it became unbearable, he'd fall into a suffocating darkness, waking with his nails digging into flesh he didn't mean to scratch raw, with vomit down his front and a migraine that left him unable to open his eyes.
His mom had never found him like this, to his relief but she had seen him after, curled up in his bed and reeking of distressed Omega that even her beta nose couldn't handle. It got easier as the years passed by though and one of the small mercies was that no one talked about your second gender designation due to anti-discrimnation laws. The only people to know for certain were the school nurse, the principal, his primary care provider, and his mother although many suspected. Kacchan had tried to test his theory numerous times after he presented as an alpha, to Order him. It had worked, making him a target for teasing when the rumors spread of him baring his neck and kneeling for the other boy. But that was soon eclipsed by the violent beatings he received. When his friend fell off the bridge into the water when they were five years old, his inner Omega had yelled in alarm and he found himself rushing to him despite being weak, scrawny and useless. He sniffed him, patted him down while looking for wounds and that had been the first time that Kacchan had punched him in the face. In a roundabout way, being screamed at and hit by an alpha everyday in middle school helped his resolve. As a result, most orders don't affect him, but on occasion they would send him spiraling into the darkness. But only, only when he'd gotten safely away because if he ever dropped in front of someone else, someone other than his mom (the worst situation being he dropped or was effectively Ordered by a villain) he didn't know what he'd do.
After years of battling his instincts, Bakugo now seemed to think that he really was a nervous, puny beta and that he had hidden his quirk, though at times he seemed suspicious. Inko had been kind enough to put Izuku on scent patches almost the day he presented which definitely helped carry the lie. As he moved through the years until he reached high school age and learned to handle his own (weak) constitution, he told himself there had to be a way for him to keep heading towards self sufficiency. He could still be a hero if he got himself under control and while he might only make it into the support program, he would go to UA; he’d be the first omega to attend, he noted though he found no exclusionary policy.
But he had to get into shape, he thought at fourteen because he had read enough magazines to know that omegas with higher muscle mass didn’t have as strong of smells, plus they had an easier time passing as betas. Another by product of extensive exercise was a lack of heats (he didn't experience them right now, something his doctor thought was related to his anxiety levels and low body fat). He would never be big enough to pass as an alpha, though some omegas were able, but another thing he had read...it was disappointing that he had to wait until he was 18 (or had his first child, sickeningly enough) to go on suppressants but in the meantime he bound the glands on his wrists and neck. It was painful and these areas were so sensitive naturally, but resources online told him that by controlling the release of pheromones, he could get a better handle on himself. The bands were coated in a waxy, slow release suppressant, the lowest dose you could get without a prescription. They were expensive and while it was agonizing to pawn some of his All Might collectibles, it was necessary. It helped on top of kneeling meditation, controlling his diet and by exercising often, and while it was a temporary fix he soon received something far more effective.
He never imagined he'd meet All Might, or that he would suddenly have a way to achieve his dreams. Izuku could be a hero, he had been told, but he had to learn discipline, had to transform his scrawny body and make himself worthy. And he had 10 months of training to do it before he received the number one quirk, him, a useless Omega. If he was one thing though, he was stubborn as hell and ten months later, he stood on the clean beach with lean but obvious muscles, muscles unbecoming of an Omega. His mentor likely had no idea how the infrequent pats on the back and ruffling of his hair helped him come back to himself each time his Omega nature threatened to overwhelm him. He had wanted to give up so often but... the smell of an alpha and their approval was enough to get him to eat, to drag his bruised body the the beach despite a lack of sleep, despite bruises from bullies, despite leftover headaches from entering a distressed state alone in his bedroom. From here on out he had to think and behave like a beta and betas...betas didn't drop.
Well, he guessed that went out the window when his protective instincts sent him skyrocketing towards a zero pointer robot, shattering his arm and his legs. Good thing the bands had tapped down the soothing pheromones his body had tried to release as the girl vomited from quirk exhaustion. But he felt content knowing he had saved the girl, and when he received his admission letter with 60 rescue points, he guessed being an omega did him a favor in the end.
He still cried at the drop of a hat, shook when his adrenaline started pumping, stared with dilated eyes as an Omegan growl threatened to rise in his throat but he had a handle on himself, always able to hide away if he felt himself slipping or stop himself if he started to act submissive. A lot of times the bands pressing into his swollen glands, the scent of unfamiliar betas and alphas around him at school, and the smell of Bakugo who had once told him to jump off a roof helped him. His fear could be used to ground him, even if it meant he would break down as soon as he got home. It worried this mother every time he came home like that, or with some injury but...he was fine. He was fulfilling his dream. Things were going so smoothly until...he made friends.
It should be a good thing but he had never realized that betas and alphas could be just as tactile as omegas, or maybe they weren’t; they were just more thoughtless about touch and what it would mean to a needy Omega (well, it wasn't like they knew). But when Ochaco casually brushed his bangs out of his face or cuddled into his side...the bands on his neck and wrists burned and burned. When Iida grabbed his arm to lead him somewhere or patted him on the shoulder, speaking to him with so much respect and his usual seriousness...his praise meant so much, not only because he was an alpha but because he was always sincere. Even Aizawa throwing him a bone in class for answering right or complimenting his progress in training often made him lightheaded and giddy. He cooked sometimes for this friends, brewed coffee for his teacher and delivered it before class, fussed over the occasionally sick or hurt classmate though he hoped they thought it was just his caring personality and not a need that he had as an omega. Being allowed to do this even to a small extent (and he tried, really tried not to go overboard) seemed to help him with any bad feelings. When he was thanked for it, that's when his arm and neck glands hurt the most but the real trouble came with Todoroki.
His friend hadn’t had the easiest childhood, having been pushed to be the best all the time; immediately Izuku felt his inner Omega stir when he was told about his father and how he got his scar. At first it was fine because his friend was very serious, standoffish, and while he might have only been a beta, he was powerful. But then they started to really get to know each other and actually, Shouto was adorably shy, kind, and smart and the more acclimated he became to having friends, the more he took initiative and wrapped an arm around Izuku, or patted him on the head or even offered Izuku his coat if he became chilled. He’d share food with Izuku and walk with him between classes, and to the dorms when they moved in. They’d spare together and then Shouto would ice his bruises, compliment and praise him until the omega’s head was fuzzy like it was full of cotton. Then, the pain would come, reminding him he couldn't be an omega.
Izuku had come close to entering a drop four times at UA. A quick phone call to his mother had sorted him out once. Then, a visit to Recovery Girl who had immediately spilled the beans about his gender to All Might but promised to keep it otherwise a secret, had eased him down. The other two times...a video recording that Shouto had sent him during his internship...the sound of his voice was enough to get him through it. He wasn't even saying anything calming or romantic but Izuku had listened to it on repeat with earbuds, kneeling on his floor as he endured wave after wave of anxiety and dread until he was exhausted and his legs were numb. He had actually dropped twice, first after the kidnapping of Bakugo but he had luckily seemed more wounded than anything to any onlookers. With the bands on and with scent blocking patches on his shoulders, they couldn’t smell his distress, no matter how strong of noses the alphas in their class had. The hospital had taken care of him and to his embarrassment encouraged him to seek alpha-omega counseling; his mom had gotten a pamphlet apparently. The second time it had been their final exam, his omega instinct far too protective to let All Might hurt Bakugo and to leave him behind. He had carried the other boy with a broken back over the finish line and the next moment he was in Recovery Girls office, swaddled and being calmed by the guilty but soothing pheromones of his mentor. It had been a truly frightening drop and he learned later that they had almost considered transporting him to a trauma unit, before he woke to an alpha Order. That had embarrassed him and so ever since he had tried to keep a better handle on things, always appearing cheerful and never giving anyone a reason to worry.
But he supposed the record couldn’t last. He’s already on edge because of the new quirk development and when he almost hurts Ochaco his protective instincts make him feel sick and he skips dinner that night, hiding in his room instead. He knows no one blames him but if Shinso hadn’t been there...he tries to hide in his nest, feeling the same smothering sensation that warns him of what is to come. The bands feel like they are cutting into his flesh and they might be; the swelling had been getting worse lately but no amount of massage soothed them. He might have to go to Recovery Girl who had agreed to see if they could find some oral suppressants but he knew they weren’t easy to acquire. The most she could do was make him sleep until he didn’t feel like tearing into his own skin.
Falling to his knees, he thinks about the sound of Shouto’s voice telling him about his dad and how irritating his father was over and over, then briefly talking about the weather in the city, but he doesn’t think that will be enough. He could call his mom but it just makes him feel worse. He wants her here. He wants to be held and rocked, with someone real cooing to him and telling him he is okay, that they know he didn’t mean to hurt his first real friend. Panting, he hates his nature so much and a sob breaks free, though his hands come up immediately to smother the rest. The room is spinning and although he has his forehead pressed to the floor, he still feels like he is falling. He hurt her, he hurt her, he hurt her- the darkness consumes him and he screams over and over into it, the echo slamming back into him. He hurt her and he could hurt everyone else-
Suddenly, he feels himself being lifted and he flails, hands coming to grasp...he can barely recognize them but they smell like beta and calm and worried and soothing. He clings to them and then everything turns black again but it’s...different. He feels safe if overwhelmed. There are so many sensations but he can’t see, can’t keep track of the sensory input. He recognizes the vibration under him and a voice that is oddly muffled. For what feels like hours, he can’t figure out which way is up and which way is down. At some point he starts mumbling and it isn’t until the later half of the drop that he realizes his mumbles are being answered. He’s being praised. He’s being held. He is...he’s being massaged. He pulls back, his vision blurry and unfocused but he can feel that his neck is bare and the hands on his wrists that are keeping him from escaping are against his skin. Alarmed, he looks down at the person who had let Izuku snuggle into his chest to find Shouto looking up at him with concern.
“It’s alright. You can lay back down.”
“Oh no. Oh no no no, “ Izuku didn’t think he could feel worse but then thumbs are pressing into the glands at his wrists and he sees stars. He groans, collapsing back on top of his friend and squeezing his eyes shut. Pheromones fill the room and oil beads on his skin but his friend takes it in stride.
“It’s okay. I’m going to help you, you understand? Anything you need-”
There’s a disapproving click of a tongue and even if the beta’s voice lacks the edge of an alpha, it still works wonders, “ You’ve done everything I want, Omega. You’ve done good. Now I just want you to rest and listen to me, okay? If it is okay I'm going to keep holding you. If you want me to let go, that's fine but you can't scratch yourself, okay?”
“Okay, “ he slurs.
Shouto tucks his face into the side of Izuku's neck, kissing the bruise that was left by the band; it was dark and painful looking but he could smell his contentment slowly blossoming. His distress was evaporating (thank goodness because it was suffocating) and so the white and red haired beta continued to try his best to soothe his friend. He had questions but they weren’t important; the only thing that was important was getting Izuku through this.
“You’re so strong, so brave. You’ve done so well. I’m proud of you.”
Izuku whimpers but it’s not an unhappy sound.
“ You’re perfect. I’m so lucky to have you in my life. You’re doing so well right now, listening to me.”
“She’s fine. She loves you. You didn’t hurt her. All of our friends love you. And I think even the teachers have a soft spot for you.”
Izuku whimpers again and Shouto nuzzles him, scenting him perhaps more than his necessary. He should probably get Recovery Girl because he knows drops can have serious psychological consequences. He hadn’t even known his friend was an omega and he wondered how much of his nature he had been concealing, and how much of his health he had been neglecting. If the bands were any indication then it had been some time. He had never seen something so horrific. How could Izuku even breath, or use his hands with them so tight? And the sour smell that had come when he’d first massaged the dark glands, the bloody oil that he had to dab away with the tissues on Izuku’s desk... It worried him, the amount of pain Izuku was in at first but he could see now that he had provided some kind of relief; he guessed taking that safety class on different genders had been really helpful after all.
“You’re fine. You’re here with me. You won’t hurt me.”
At long last, Izuku looks at him with some clarity though his pupils are odd looking. He sits up shakily, their legs tangled and he pushes himself away from Shouto. He looks so ashamed but the beta won’t let him get away with that. He knew his friend was self destructive but this was a new level; he doesn't let go of the Omega's wrists, holding them loosely given how red and irritated they are, “ Don’t apologize.”
Izuku cuts himself off and for a long moment, no one speaks.
“ I came to check on you. I brought you soba. Thought we could share.”
The green haired man nods.
“I...I knocked but you didn’t answer. You didn’t lock the door and I got worried. I’m sorry if...I wasn’t sure how to handle it but you were so low. I was scared.”
“You did everything right. You...thank you so much.”
Shouto can hear the unspoken apology and he reaches up as if to touch Izuku’s cheek but the boy flinches; the fire and ice user frowns but tries not to feel bad, “ Anytime. Any moment you need me...tell me. You shouldn’t feel ashamed asking. You can’t bottle this up. You’ll make yourself sick.”
“Please...no one can know. I can’t be an omega and a hero. “
“You already are, “ Shouto says, “ You’ve inspired so many of us. You have saved people, myself included. And you did that by being you. It was you who told me to embrace myself. Now I'm telling you to do the same.”
Tears drip down Izuku’s face and the beta tries again, caressing his cheek and moving his bangs aside. He sees that his neck is looking better with every minute and while the room is saturated with pheromones, the sour smell is being erased by the smell of contentment and hope. Shouto manages a small smile as he continues to touch the omega who seems to be going more and more limp until he’s once more pressing his face into his friend’s chest. His cheek had found the tiniest bit of exposed skin to press his nose to near the dual quirk user's collar. He knew Izuku’d go back to being a strong, unshakable beta tomorrow but if he could have a reprieve now and just be himself here with Shouto, who could be a balanced beta capable of comfort instead of the stoic alpha his father tried to force himself to be...
“ Rest. “ he tucks Izuku's body even closer, “ You don't ever have to hide, not here, not with me.”