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It started out simply.
Izuku didn't think too much about it at first. It was normal for details to start slipping when you are finally able to relax in what used to be a high-stake environment, where every misstep could have led to your death. He doesn't mention to All Might how much it hurts that he can't remember his father anymore, the name of Mom's favorite flowers, and the first time he watched his debut video.
He doesn't falter when he can't remember the doctor's appointment that ruined his life or the first time Katsuki turned on him and hurt him. After all, it was better like that. What use was remembering bad memories?
He doesn't falter the first time his mother fondly tells All Might a story about his childhood and he can't for his life remember it. He just nods with a forced smile and laughs with them.
He doesn't falter when he can't remember the Sludge Event and how he met Uraraka at the Entrance Exam.
He doesn’t falter when it slowly affects his grades as well. Mundane things slip his mind easily. His position drops slightly and he knows that his friends and teachers are worried about him. But still, he pretends he is okay. That everything is fine.
He isn‘t fine. He wants to scream for help but every time he tries, he can't find the words.
It’s only on a Thursday night when Izuku realizes how much he is truly broken.
He is taking the trash outside when Katsuki corners him.
Izuku startles and turns to the blonde, who looks enraged.
"Kacchan?" he brings out shakily, gripping the handle of the trash bags until his knuckles turn white. "What- What are you doing here?"
The older boy narrows his eyes at him.
"Kacchan?" he tries again.
He flinches as Katsuki's right palm explodes against the wall next to him.
"Is this some sick joke?!" the teen screams and invades Izuku‘s personal space.
Izuku takes a step back, helplessly staring at Katsuki‘s crimson red eyes.
"W-What?" he stammers. "I have no-no idea what you are talking about."
"Did Icy-Hot and Round Face dare you to do this?"
Izuku‘s left eye twitches in annoyance.
"Or Horns and Pikachu?" The blonde-haired boy shoves him, making him let go of the trash bags. "Do you think this is funny, heh?"
Izuku can feel the anger starting to build up under his skin and he balls his fists until he can feel his nails digging into his palms, hoping the pain will counteract the stored-up, hot fury bubbling inside him.
Katsuki pushes Izuku again, this time stronger, and Izuku almost trips over his own feet.
And Izuku snaps.
"What the hell is your problem?!"
Katsuki looks shocked for a few seconds before his face morphs into anger again.
"It‘s my fucking birthday, dickhead!" he screams. "And you don‘t congratulate me?"
He points at himself.
"You were always the first. May it be over text messages or at middle school, no matter what I did or where I was!" he continues. "And suddenly you forget? Don‘t fuck with me!"
"Who put you up with this!" he questions again, fuming.
But Izuku is too stunned to answer.
He didn't remember.
He didn't remember Katsuki‘s birthday.
He sinks to his knees and stares at his hands in shock, too dissociated to notice what Katsuki exactly does in response.
"Hey, what the hell?" he hears a muffled, frightened angry voice. "Nerd, what‘s wrong with you?"
He thinks someone is shaking him, but before he can attempt to move through the fog, to get back to consciousness, someone snips his strings and he slumps in himself, the world plunged in darkness.
Until he wakes up, blinking at seven and a half-transparent forms.
Izuku crawls at the mist surrounding his jaw and lips with wide eyes.
A white-haired man approaches him. Izuku doesn‘t remember his name.
"I‘m sorry Nine," he says solemnly, hesitating before continuing. "We thought you were like Eight. But it seems like One For All has gotten so strong that even an empty cup can overflow."
He smiles sadly, eyes full of remorse.
"I‘m really sorry."
The forms slowly start to dissipate.
"But remember that One For All's legacy is finished," he says hurriedly. "Remember that you are allowed to rest."
The next time he becomes aware again, it is to hushed voices talking.
"And what about him forgetting stuff?"
"Maybe he was just stressed out," a gruff voice offers, although sounding doubtful.
"No," a younger voice interrupts. "You don‘t understand. Deku- He would never forget-"
Izuku groans and the voices stop talking.
He blinks against the bright, fluorescent lights as he stirs awake.
Izuku sits up, one eye squinted together, and looks around before sighing.
He‘s in the infirmary again.
He slumps against his pillows in defeat.
A dark-haired man with a white scarf approaches his bedside.
"Hey, kiddo," his voice is raspy but soft. "Do you know who I am?"
Izuku tilts his head.
"Eraserhead?" he questions and the man seems to get more relaxed and there is relief in his eyes, until- "What are you doing here?"
Eraserhead‘s eyes widen.
Izuku looks over his shoulder to Katsuki and Recovery Girl standing there.
"Problem Child."
Izuku doesn’t react.
"Problem Child," Eraserhead tries again, voice more tired. "I‘m your homeroom teacher. Do you know where you are?"
"Of course," Izuku says. "I'm at UA, I‘m in the hero course and my homeroom teacher is... is..."
He trails off.
He can't remember.
"It's me."
Eraserhead points at himself and Izuku frowns.
He never noticed it before, but there is a white, blurry dot in his memories. On his first day of school. At USJ. At the press conference before Kamino. At the Shie Hassaikai Raid. At the war.
That was Eraserhead?
Izuku sinks into his pillows.
He much is he forgetting?
The resignation in Eraserhead‘s eyes changes into determination.
"Everything is going to be alright, Problem Child. Trust me," he states seriously.
And somehow Izuku does.
Because, while he doesn‘t believe in his words, he trusts in his actions.
He trusts in what he has read about the underground hero in forums and quirkless discord servers.
He trusts in the whispers that he never discriminated against people without quirks or quirks which were seen as disgusting, villainous, or less.
He trusts in what he can remember.
He trusts in the muddy snippets of a faceless person protecting him and standing up for his class.
So he trusts.
He trusts and hopes that it isn‘t misplaced.
Recovery Girl wants him to stay in the infirmary for a few more days while she runs tests.
Nobody wants to tell him what exactly happened.
Eraserhead still hasn't left the infirmary, having gone in front of the room after receiving a call.
"I'm worried about him,“ Eraser- Aizawa says with an exhausted undertone. "Not only..." he seems to hesitate. "you know, but him suddenly forgetting such major points of his life? It's not normal, even after what happened.“
He knows he is talking about him.
"I'm not sure," Aizawa says hesitantly after a while. "I have a feeling Chiyo is hiding something from me. And Bakugo knows more than he pretends to as well."
Aizawa sighs in response to the other person.
"Yeah, probably," he responds. "Any idea why the blond buffoon still hasn't come? I always thought Midoriya was his favorite."
Aizawa clicks his tongue.
"Still thanks, I'll see you later. Tell Eri 'I love you' from me, alright?"
Aizawa hums and a few minutes later the door opens to the infirmary and he strolls in. The man looks exhausted.
"Eraser-" Aizawa gives him a pointed glare. "Aizawa-san," Izuku hesitates. "You don't have to waste your time with me."
The underground hero scoffs.
"I decide what or who is wasting my time, Problem Child," he counters. "And you are one of my students. You are my responsibility, it's my job to keep an eye on you."
Izuku opens his mouth to retort but closes it when he doesn't find a suitable counterargument.
He slumps against his pillow and pouts.
He still doesn't like it.
Aizawa looks at him amused, the corner of his lips twitching as he sits down near his bed.
"I know you don't like it," he says, correctly guessing Izuku's thoughts. "But it's the truth. Just rest and get better. That's all I ask for, alright?"
Izuku hesitantly nods.
Aizawa smiles at him as he leans forward and ruffles Izuku's curls.
Izuku doesn’t even startle to his own surprise, involuntary leaning into the touch like a cat, drawing a laugh from the underground hero.
"At least, this hasn't changed at all."
Izuku feels his face heat up as Aizawa leans back.
"Get some rest kiddo," the man tells him before standing up. "The hellspawn are visiting you later."
Hellspawn? Does he mean their class?
Aizawa goes out of the infirmary, holding the door up for someone as he nods at them.
A second later, Katsuki enters, still wearing parts of his school uniform, his jacket thrown over his shoulder.
He slouches in the seat Eraserhead was seated just a few minutes prior and drones out a tired, "Hey nerd."
Izuku smiles in response.
"Tough day?"
Katsuki rolls his eyes.
"You have no fucking idea," he groans. "Your whole brigade was up my ass asking how you are."
"Kacchan," Izuku laughs out.
"Don't laugh," Katsuki replies in an annoyed tone, but Izuku notices how he tries to suppress his smile. "It's true. The whole class is head over heels for you. Better get some rest like Aizawa-sensei said or their energy will slam you like a truck when they are allowed to visit you later."
Izuku nods, still laughing, while Katsuki averts his eyes.
It's quiet for some while, both just sitting and saying nothing.
"Kacchan?" Izuku hesitantly prompts, waiting for the boy to hum, before he continues, "I'm sorry I ruined your birthday, I.. I really-"
"Shut up!"
Izuku looks at the boy with wide eyes.
"Don't you dare fucking apologize for that!" Katsuki leans forward, almost growling, "What matters is that you are healthy right now.. Do you have an idea how scared I was when you broke down like that?"
Izuku is too stunned to answer.
"I don't give a fuck about all that shit. Deku," Katsuki interrupts himself, shuddering. "Izuku. You looked like you were fucking dying. I don't think anyone told you but you had a fucking epileptic seizure before blacking out. For all we know, you could have died. And I could have done nothing!"
The teen pounds on his own chest with a closed fist.
"So don't you dare apologize to me for that!"
Izuku nods with an open mouth.
"I'm-" Izuku stops himself when Katsuki narrows his eyes at him and holds up his hands instead. "Okay, okay. I understand."
Katsuki scoffs and leans back, staring at the ceiling.
"It's One For All's fault, isn't it?"
Izuku flinches.
Katsuki chuckles darkly.
"Even now that fucking quirk and asshole are finding a way to fuck you over."
Izuku grips his blanket.
"I can't access the other quirks anymore," Izuku reveals in a quiet whisper, Katsuki close enough to hear it.
"You can't- What? Since when?"
"Since we defeated All For One and Shigaraki is in custody," he admits.
"Fucking hell," Katsuki groans.
"They," Izuku doesn't need to specify who, "are gone now as well."
Izuku has no idea how to explain it to his friends and everybody else.
Katsuki had stopped him from going rogue back then when he had found the letter, mere seconds after Izuku had delivered it to him. He had stopped Izuku from doing the same to their teachers and the rest of their classmates.
And since then Izuku didn't have the courage or energy to reveal One For All anymore.
Everything just went too fast during the war and after that, they had to rebuild the entire hero system and structure.
Sure there are people who are suspicious or have their own theories — All For One wasn’t really known to pass up a chance to monologue — but everybody just assumes that Izuku is All Might's protegé like Shigaraki was once All For One's and leaves it at that.
Nobody knows the real reason he was targeted, why All For One wanted him so desperately kidnapped alive and not dead. Nobody knows about One For All. Nobody knows that he used to be quirkless.
Izuku was just too afraid to tell them everything. Even now, he is still afraid of their reactions.
What if they thought he couldn't be a hero because he used to be quirkless? What if they would see him as weaker? What if they prove his fears right?
"We," Katsuki breathes in heavily, "We have to tell someone."
Izuku freezes.
"Aizawa-Sensei deserves to know," Katsuki adds. "And I have no idea how long we will keep up the lie. How long until this secret will break around us like glass."
Izuku stares blankly forward.
"I," Katsuki swallows, "I know it isn't my decision, but please think about it, okay nerd?"
Izuku just nods and the blonde-haired boy leaves without saying anything else.
His friends look nervous when they approach his bedside, bearing awkward smiles. They are the last group to enter, his other classmates having visited before them.
Izuku had fondly listened to Kaminari and Mina talking about some little, silly stories that happened while he was unconscious and not present.
Then, he petted Koda's rabbit, nodding along as Shouji and Tokoyami discussed a topic that was brought up during art history with Midnight.
Iida brings Izuku out of his musings as he starts to talk.
"I have compiled everything you missed so far so you don't fall behind."
Izuku smiles.
"Thanks, Iida."
He takes the notes Iida is holding out and places them on the bedside table to look through later.
"Did Recovery Girl tell you when you will be released?" Uraraka pipes up, having settled on an extra stool next to Iida, the rest — Shouto and Tsuyu standing off to the side.
Izuku shakes his head.
"It depends on what the results are I'm guessing," Izuku answers, before brightening. "But we did finish all of the tests so at least I can properly relax now."
"Did she mention what tests she is doing?" Shouto asks in an almost monotone voice, but Izuku can hear the concern ringing through. The boy still struggles with properly conveying his emotions.
Izuku hums as he thinks back.
"I'm not sure she did. But she did draw blood among other things, so I'm guessing some time of blood test?"
Shouto nods, apparently satisfied with that answer.
"Now that I'm trying to remember, she did want to schedule an MRT, but it was too hard to get one on such short notice."
His friends share some worried glances.
"Did someone tell you what happened at Bakugo's birthday?" Tsuyu's question cuts through the tension like butter.
"Asui!" comes the mortified response from Iida, the boy flailing around his arms in a chopped manner. "We agreed on not bringing it up!"
"I told you to call me Tsu, kero," the girl replies bluntly. "Also, Midoriya deserves to know."
Izuku can see how Iida's right eye twitches at that. He stands up, reprimanding her further.
"You know exactly who told us to not bring it up!"
"Guys-" Uraraka tries to interrupt hesitantly, but she gets spoken over by Tsuyu who also seems to get more agitated with each moment. Shouto looks between the two, looking lost.
"It's his right to know that he almost died," the girl down-right hisses.
His friends freeze, suddenly remembering in front of who they are having this argument. Shouto and Uraraka look as exhausted as he is, probably having heard that discussion before.
Izuku, for once, doesn't suppress the heavy sigh that comes out of him.
"Kacchan already told me," Izuku admits. "And Tsuyu is right, I have a right to know."
The girl looks smugly in the direction of Iida.
"But I also don't appreciate my friends fighting."
At that Tsuyu looks ashamed at the floor, Iida not meeting either of their eyes. Izuku sinks into his pillows, dragging a hand over his face.
"Deku-" Uraraka tries to speak up but Izuku interrupts her, holding up a hand.
"Go."
His friends hesitate.
"Go!" he repeats a bit more fiercely, squeezing his eyes shut.
And Izuku lets himself break as soon as he hears the door click shut.
It's late at night when Aizawa returns with Eri in tow.
"Eri!" Izuku exclaims with a smile, not minding when the girl climbs onto his hospital bed.
"I'm sorry, I know you are probably tired after everything today," Aizawa sighs — and the man is right, Izuku is tired, his mind replaying Katsuki's words and Iida and Tsuyu's confrontation in his mind, over and over again. "But she really wanted to see you."
Izuku waves it off.
"I could never say no to her."
Izuku never told anyone, but he only remembers meeting her for the first time and the aftermath of the raid. He doesn't even remember the raid or his internship. If it weren't for the memory of Sir Nighteye dying and Mirio being there, Izuku's memory issues would have been noticed way earlier.
Although it was weird for Izuku to have Mirio acting so familiar with him - only knowing him from memories of passing and the first fight, he had gotten quickly used to him inviting him to lunch with his other friends.
All in all, he is sure the older boy never noticed that he doesn‘t remember his internship or the raid, considering they only talked about Eri.
He lets Eri excited rambling wash over him, relaxing into his pillows as he braids her hair.
Unbeknownst to him, he starts humming a melody under his breath while he carefully plucks apart strands of silver-white hair.
Until the girl in his lap stills and stops talking in favor of turning around with bright eyes.
"Hey hey, I'm not finished yet," Izuku scolds lightly and her eyes widen. She quickly turns around and Izuku laughs.
"What is the song you were humming?" she asks after a while of silence, Izuku close to finishing the simple braid.
"The song I was humming?" Izuku repeats, bemused.
Eri nods.
"It's a lullaby my father used to hum to me," Izuku explains softly as he remembers back.
He is surprised he still remembers that particular memory, considering the recollection of his father almost faded into nothingness. That memory of the man is the only one he has left of him. He can't even remember his face.
"Where is he now?"
Izuku stills.
"I don't know," he answers solemnly.
He never bothered to ask his mother about the man. And what little he knew of his family is now lost. Forgotten.
Eri seems to pick up on the downed mood and she twirls around as soon as he finished with the braid.
"I have two dads!" she exclaims. "We can share!"
"You can't just decide that on your own!" he laughs out.
"Why not?" She pouts. "You're obviously family!"
"I'm sure Hizashi wouldn't mind having you, Izuku," Aizawa interrupts, amused.
"Don't encourage her!" Izuku shouts scandalized, ears red.
"Can you believe that Eri? Your nii-san doesn't want us anymore!" Aizawa teases and Izuku buries his face into his hands.
"Stop!" Izuku groans, the sound muffled.
And as Izuku sits there, face red, with Eri giggling and Aizawa laughing, deep and hoarse, he remembers.
Ah, that's right, that's what family feels like.
Izuku doesn't know why, may it be his subconsciousness at play, but Aizawa's presence never feels forced. Despite the fact that he is a white dot in his memory before landing in the infirmary, Izuku trusts him.
He trusts him, so he leaps.
!I think it‘s my quirk," Izuku brings out, during one of the times Aizawa visits him, this time alone.
"Excuse me?"
Aizawa looks bewildered.
"My quirk," Izuku repeats. "I think my quirk is the reason why I forget things."
Aizawa stares at him and Izuku tries to continue, to finally share One For All‘s secret, but his jaw locks up on him.
He tries and tries, but fails.
Frustrated tears start to form in his eyes and he clenches his fists in anger.
Aizawa is at his side in seconds, drawing him into a hug.
"Hey, hey, it’s okay," he soothes, drawing circles on his back, and Izuku bites his lip as tears stream over his face.
"All- All Might," he manages to force through, before his voice fails him, leaving him completely mute.
"I should ask All Might?" Aizawa prompts, and Izuku nods.
Aizawa squeezes him a bit harder before backing up a bit.
"Do you want me to stay with you?" Aizawa asks. "One tap for no and two taps for yes."
Izuku taps two times hesitantly.
"All right," Aizawa murmurs and holds him closer again.
Izuku just tries to gulp down his sob as he tightly clutches the sem of Aizawa's shirt.
He fails miserably.
It's one day later, that All Might comes.
He looks exhausted and even more pale than usual, bearing deep, purple eye bags.
"I talked to Aizawa-san," he starts. "And I.. I have not been entirely truthful with you."
Izuku doesn’t interrupt the older man and lets him talk.
"Nana," his voice breaks, "Nana was the same," he gulps, "the same as you."
"The quirk was wearing her down, eating at her memory. She got worse and worse until she was only focused on All For One. Before I could do anything, she headed into battle and never came back," his voice sounds hollow. "I- I thought it wouldn’t happen again. I was prepared for it to happen to me. I even set up safety procedures." His hands shake. "But I was never prepared for it to happen to you.“
"I'm sorry Izuku," All Might apologizes, bowing deeply. "I'm so sorry."
"I forgive you."
All Might's head snaps up.
"My boy, you don't have to-"
"No. You don't understand All Might. You gave me a chance for life," Izuku interrupts. "And despite everything One For All did and will do to me, I wouldn't even be here without you."
"Izuku..."
Izuku doesn't meet his eyes.
"I may not remember the day we met anymore, but I remember what it was like to be quirkless before you gave me One For All."
He hears a gasp and remembers that he never told All Might how much he has already forgotten.
"You don't remember..." All Might trails off.
"It's in the past anyway," Izuku smiles to hide the pain.
From All Might's face, he is failing.
"How much did you already forget?" he questions and Izuku looks away, biting his lip.
"Not much," he lies — so much.
So much he will never remember again.
He suppresses his need to cry.
Suddenly All Might is drawing him in for a hug.
"You don't have to pretend with me Izuku," All Might murmurs into his hair, and Izuku breaks.
"I'm just so tired All Might," he rasps out, tears streaming down his face.
"I know Izuku," he replies shakily. "I know."
After All Might’s visit, his condition rapidly deteriorates.
He forgets more and more. The memories slip through his hands like sand.
Recovery Girl and Aizawa want to keep it from him, but he knows. He notices. From the way, he is getting more and more forgetful, not remembering meetings when people bring them up and not being able to pin-point names to faces.
He notices the arguments they have. How they get more agitated and desperate when there is another person he doesn‘t recognize, another memory he forgets.
He notices from the way his mind feels like a thick fog. How he can’t grasp at his thoughts, everything feeling muddy and heavy.
He notices. And others do too.
So before he forgets everything, he at least wants to properly say goodbye.
From the way everybody freezes in their places and go deadly silent, they didn‘t expect Izuku to come.
So Aizawa didn‘t tell them.
He follows Aizawa to the podium, stepping behind him, and closes his eyes as he breathes in.
He just opens his eyes when he hears Aizawa stepping away after telling the class why he is here.
He stares at the two-toned boy with the scar, the brown-haired girl, the girl with the frog mutations, and the tall boy with the glasses before speaking.
He knows that they used to be his closest friends.
That‘s what he wrote down in his notebook before forgetting every memory he had with them.
Aizawa, Katsuki, Recovery Girl, All Might, and Eri are the only people he doesn‘t forget because they regularly visit him with updates or just to spend time.
When the others of his class come, he catches their names and remembers them, but it slips away as soon as he doesn‘t have a visible reminder.
"My quirk is called One For All."
Strangely enough, that is the only thing he doesn’t seem to forget no matter what.
"And it‘s the reason I‘m forgetting everything."
He looks at Katsuki because it is easier.
"Through an MRT they found out that the quirk factor is attacking the neurons in my hippocampus." he explains. "If I‘m being honest, I wouldn‘t even remember your names, weren‘t it for Katsuki and my notebooks."
Katsuki doesn’t flinch at the name of his given name — not anymore. He knows that he used to call him a nickname, but even that slips him away every time he tries to remember it.
"Apparently before I got One For All, I was quirkless," Izuku reveals. "But even that I don‘t remember anymore."
He can hear some people in the class gasping and sobbing, but he stubbornly looks into Katsuki‘s crimson red eyes.
"They don‘t know how to help me," Izuku says. "So I want to say goodbye because I don’t know how long until everybody will seem like complete strangers to me."
How long until they don‘t even seem familiar anymore.
How long until he will even forget Katsuki, Aizawa, and the rest.
How long until he will be only a shell of himself.
He clenches his fists.
He hates that he waited so long to do this.
He wishes he could have said a real, proper goodbye.
Izuku finally tears his gaze away from Katsuki to look into his classmate's eyes.
For one last time.
"Sayonara."
Izuku stares at the white wall and counts the tiles on the ceiling.
He gets interrupted at the number 34 — needing to start almost every few minutes when the previous number slips his mind — when the door opens and a middle-aged woman with green hair comes in.
She seems oddly familiar — a feeling he didn’t have in a long time — but Izuku can‘t place her.
He tilts his head at her and she looks at him with expectant eyes.
Like everyone does.
Izuku sighs before speaking up.
"I‘m sorry," Izuku says, rehearsed. "Who are you again?"