Chapter Text
Midoriya Izuku’s house was filled with tension. At least, Izuku always felt the thickness of the air weighing down on him, even as a small child.
Inko and Hisashi Midoriya, Izuku’s parents, never seemed to feel the tension like he did, or if they did, they never made any comment or indication of acknowledgement. Maybe it was because the tension was only between Hisashi and Izuku, and Inko always found a way to diffuse whatever thickness in the air existed between her and the other cohabitors of the house. Whichever it was, it left Izuku tense and unable to relax on the good days. On the bad ones, Izuku was left sobbing silently in pain, while the house’s foundations groaned louder than he did. (Those were rare in the early days. But not so much just a few years later.)
Izuku was scared. But he was also resigned to it. He didn’t know how to stop it, so he subconsciously tied himself to his fate, sink or swim, since he knew nothing else.
His father, and his father’s side of the family, for that matter, were absolutely terrifying to Izuku just based on what he knew about them. Or rather, what he really didn’t know about them. He knew that his grandfather on that side ran some sort of business, and that his father was working in whatever it was, but only knew that it couldn’t be good, based solely on his father’s demeanor. It was one with a facade of placidness and calmness, but with a seething turmoil of anger and hatred just under the surface, waiting for the right moment to boil over and burn anyone too close.
Whenever his father was in the house, loud noises made Izuku jump, the tension dictating absolute quiet. Izuku made himself small and unassuming — especially when Hisashi was close, even if no one was looking at him. And most especially when Hisashi was staring down at him with blood-red eyes.
But the tension didn’t break for a long time. (And it wouldn’t for a while more.) It told Izuku to be careful around his father, to carefully not disturb the quiet peace in his house, unless Hisashi wasn’t home. When he wasn’t home, Izuku could be himself — the happy go-lucky child in love with heroes — without the worry of repercussions. Inko didn’t seem to care, allowing Izuku’s repression when Hisashi was home, but also allowing his decompression when her husband wasn’t there.
Inko’s allowance towards Izuku’s attitudes continued during those short periods of laughter and joy within their household. Nothing stopped him from this joy for heroes after he gained some freedom at his day-care, where every day had some aspect of heroes ingrained within them, whether it was a lesson, a coloring page of All Might, or a game of heroes versus villains during recess with his classmates.
But that excitement wasn’t allowed to exist around Hisashi, or even within the relatively safe confines of Izuku’s own room. Hisashi made it clear when he banned the word “hero” from his presence and with his fiery glares. The one time Izuku tried to bring it up in his presence had left him curled up around his hand, which Hisashi had clawed and spat fire onto its back “as a reminder never to say that word around me again,” even as Inko stared on glassy-eyed. (It was the first and last time Izuku fought against the tension in their house.)
Izuku held off more injury by waiting until Hisashi vacated the room to the bedroom, after completing his dinner of course, to begin to cry with the quietest sobs he could, already knowing that creating more sound would only be worse, as he gently pulled his hand toward his chest and the limb began to tremble with greater and greater intensity.
As she cleared the dinner table after the encounter, Inko reached down and tapped Izuku’s forearm, where Hisashi’s talons had punctured sensitive flesh, causing a violent flinch away and drawing Izuku’s attention up to her face. She said, “You deserved it. Let it be a warning to not be testy with us.”
With that, Inko finished clearing the dishes and got started on washing them, leaving Izuku cradling his left hand to his chest to deal with it on his lonesome.
That night was the first time Izuku was acquainted with the ( much too large ) stash of medical supplies in the bathroom. He found a tube labeled “burn cream” with his limited knowledge of kanji and the phone’s ability of speech to text functionality to find what the kanji for those two words looked like (he had borrowed his mother’s phone, seeing as he wasn’t allowed one). From there he searched the vast supply until he found the kanji on a tube that matched what he found online. He smeared some of the contents onto the burn carefully, but painfully, and found gauze that he wrapped his wrist and hand in, not daring to touch the puncture wounds, even as he cried.
(He would soon become much, much more used to doing this for himself, as well as knowing the best way to bind a hand injury and too many other types of injuries. Although the first attempt was sloppy, the ones in the future were carefully done to the point of near-professionalism.)
That was the first of many encounters where the tension rippled, only to return doubly, pressing Izuku’s small shoulders down, and down, and down.
Izuku would recover from the slowly lifting tension by watching his favorite video of All Might, but always did it when he was sure that Hisashi couldn’t see or hear. (After being caught once, and terrified of the anger and aggression and hatred Hisashi displayed, as he raged around the living room and kitchen, ending only after he had thrown a lamp and a vase at the wall near Izuku, he only watched it when Hisashi wasn’t home and it was only him and Inko, and sometimes, when it was just him in his room.)
Izuku didn’t understand why Hisashi did what he did. Only that he didn’t like it and it made him afraid and Hisashi wasn’t Dad but Hisashi . He couldn’t be that person, not to Izuku, as Izuku realized soon with his interactions with people outside of his family. Hisashi was no “father” based on the countless comparisons he soon made with other children’s parents, as well as how they all talked about their father’s fondly.
When Izuku was three (almost four!), he was in day-care, quickly finding and attaching his cheerful self to the other kids that wanted to play, usually after expressing an interest in being a hero. Katsuki Bakugou was one of Izuku’s first victims to this end, Izuku’s wide eyes finding Katsuki’s own across the classroom and attracting each other. Izuku’s first question was “Do you want to be a hero, too?” And from there the fragile (and temporary) bond of friendship was forged between the two.
Kacchan, as Izuku came to call him, wanted to be like All Might, and “win at everything!” Izuku could completely understand that, since Izuku adored All Might with all his heart (including all the parts that should have been taken by the strong bond usually found between father and son.) (Hisashi was no father, not to Izuku.) They bonded over it, and Izuku stuck to Kacchan while he was at school, and for some time after school ended each day.
Kacchan was also particularly interested in what Izuku kept under the bandages he still wore on his left wrist and arm, until the puncture wounds finally finished closing after two and a half weeks. Izuku had some common sense after all. Daycare had started only two weeks before. It wasn’t like Izuku was trying to avoid showing Kacchan, he just wanted the rather severe wounds (or so he thought at the time) to heal as completely as possible before exposing open wounds to the outside world and all its potential germs. The teachers didn’t care enough to even ask, which was just another reason to continue his self-treatment as best as he could. (And yes, Izuku was changing the bandages and reapplying the burn cream every night before bed, like a good toddler , setting the precedent for his future .)
After enduring roughly a week and a half of seemingly unending torment about it from Kacchan, Izuku finally showed the abuse his hand had undergone, seeing as the punctures were just small scabs now and the burn was mostly healed over, though the evidence of all the wounds remained in the new skin as scars.
Kacchan immediately went wide-eyed, a new expression for Kacchan for Izuku to be on the receiving end of, a combination of fascination, surprise, and finally, a concealed concern flitting across his face as his eyebrows drew together slightly.
“Woah Izu, cool scar!” Was Kacchan’s immediate reaction. “How’d you get it?” Was the second reaction. A reaction Izuku was expecting. But his response was immediately to lie.
There were a few reasons for what Izuku considered a small deception, one being that Izuku started to realize that no other all families (from what he could tell at least) operated the way that his own did as he began to interact with the other kids’ in class. As he learned about his classmates’ lives away from school, he realized that they didn’t have that same tension. And he wasn’t sure what to make of it, or whether or not he should reveal the differences between Izuku’s own family and Kacchan’s “normal” family, so he erred on the side of caution. After all, he had absolutely no idea what might or might not happen if he spoke about the actual cause of his injury.
The other reason was that Izuku was ashamed for deserving the scar, for his mother believing he deserved it (for disappointing her), and for believing that he deserved the punishment of his first scar, and the pain that came along with it. He was guilty of disappointing his own mother, who he couldn’t help but love dearly. He didn’t want Kacchan to be disappointed in him, too. The truth was never a viable option.
So Izuku lied and said, “Oh, I-I had an accident with scissors and some tea when I tried to hold both at the same time. I tripped as I tried not to spill the tea, and I cut myself with the scissors and poured scalding water on my hand as I fell.”
Kacchan immediately scoffed, not doubting the validity of his friend’s story, though anyone older than them could have easily tasted the deception with how obvious it was. “What kind of stupid fucking idiot do you have to be to hurt yourself so badly in only a second? And what a fucking stupid story too.”
Izuku pushed a smile onto his face over the ugly roiling of his stomach created by his lying and nodded in agreement. “Yeah, it was stupid, wasn’t it?”
They began to wander towards other kids, gathering them to play a game of heroes versus villains.
But within a few days of that conversation with Kacchan, Kacchan developed his own quirk — his birthday was four months before Izuku’s own, after all. And with it, their tentative, mutually friendly relationship also came to an end. (It mutated .)
Kacchan was obviously hugely pleased by his new quirk, explosion, and was confident in his own ability to one day surpass even All Might, even as a four year old.
Izuku himself had no such delusion, especially as his own father flaunted his own strength every night by controlling the tension that pushed down on Izuku - trying to form and manipulate and change Izuku’s very nature. He also had no doubt that Kacchan would work to become an amazing hero. But he knew that he didn’t like this change in his friend. Kacchan suddenly was receiving more and more attention from the teachers, not that Izuku really cared, but it started to go to Kacchan’s head. They praised his quirk, and told him that he’d be a great hero. None of which was wrong by Izuku’s perspective, truth be told. Kacchan has an amazing quirk, and he will be an awesome hero!
But the teachers also began to look the other way. They let him get away with turning in a form a full week late, and didn’t even consider stepping between him and his victims when he wanted to “ show how much better I am from these extras! ” They would never reprimand him when they would scold other kids for similar behaviors. Izuku didn’t really understand that logic, since they were all equals, right? Right ?
Kacchan began to truly believe he is the absolute best in the class and he would be the absolute best from their school — that no one could challenge him or would even try to do so. If the adults said so, it had to be true, right?
Izuku didn’t particularly appreciate the arrogance, already experiencing too much of it at home, but any feelings of hesitance and worry were swept away as he saw Kacchan’s motivations and strides forward towards their shared goal. He didn’t falter in this perspective for a while yet, even when Kacchan showed his knowledge of kanji and renamed Izuku to Deku, or when Kacchan hit Izuku’s hand away when he showed concern in the river. So Izuku followed Kacchan and also praised him, although less than everyone else at school, and most interactions between them were stilted because of it.
“Hey, Kacchan! You’re going to be a great hero… but I’m going to be a great one too!” was all Izuku wanted to say to Kacchan, but he knew it would only bring him pain, seeing as Kacchan’s ego was so boosted that any other kid saying that they wanted to be a hero, especially those with “weaker” quirks or those that hadn’t developed yet, would cause Kacchan to positively burst in irritation, pride, and anger. The tension began to build between the two. Seeing as Izuku’s own quirk hadn’t arrived yet, and likely wouldn’t for a few more months at least, Kacchan decided to tolerate Izuku. This “tolerance” wouldn’t last more than a week, when Izuku began the pattern of preventing his habit of bullying other kids that damaged Kacchan’s overly inflated ego. This first time it happened, nothing much changed between them. But as time passed, and more of these incidents occurred, their relationship began to strain.
“Stop it, Kacchan! You’re being mean!”
Izuku stood between the victim and Kacchan and his cronies. He wouldn’t allow this.
“Huh? And what do you think you can do to stop me, fucking Deku?!” Kacchan scoffed back, but backed off for the moment. “You aren’t worth my time anyways!”
Izuku turned to help the other kid, but found he had run away.
The next few days had Kacchan continually enforcing his own superiority over other kids and their dreams, with Izuku stepping in every time. It pissed Kacchan off to no end, which wasn’t Izuku’s intention (he really didn’t need that tension at school, too) and so Katsuki began to push Izuku away. Izuku reluctantly allowed it - he hated to see a good relationship that their own had been fall apart like it did.
He never stopped in his attempts to stop Kacchan’s bullying.
(He missed his friend.)
Kacchan’s avoidance and annoyance of Izuku left him with much more time after school that used to be play time (when he avoided going home, seeing as his parents really didn’t “give a shit” what he did as long as he was home before dinner). Although most kids Izuku’s age were just running around and playing with one another, Izuku was already eager to absorb information. Sometimes adults would comment to each other after seeing him in action at school and the library that it may be an early activated quirk, as Izuku easily and rapidly learned kanji and even English (though without a major grasp of certain more complicated words and patterns or grammar in both subjects, though he still gained skills to improve in each).
After integrating those reading skills quickly, nothing stopped him from wanting to write and read more and more. He loved it! So nothing stopped him from pursuing it, seeing as he lost his one good friend, and seemed to have put him into this gray area with the rest of the class where no one wanted to be his friend or his enemy, for whatever reason. Basically, Izuku had a lot of time to spare after school — though he usually cut these knowledge pursuits somewhat short to be home with some time to spare.
Izuku quickly became the local library’s youngest (and, unbeknownst to him, most beloved) client at nearly four years old, and transitioned from children’s books to more advanced chapter books within a week of having the membership (which didn’t actually cost anything -- there were costs only if books were overdue, and Izuku was never late). It was lucky the library was only two blocks or so from his school, and only a few more to his home. It was right on the way to and from school, although it was near the edge of the city.
Any books Izuku took from the library he was careful to return on time, or renew the book if he needed more time to understand it or just finish it. He couldn’t afford late fees after all, being a (almost) four year old. He was also careful to read them out of sight of Hisashi, since Izuku couldn’t be sure what the reaction of his learning would be. (It was a benign hobby, one most parents would praise. But Izuku was scared of being caught with them due to Hisashi's generally fiery temperament.)
It was with mild encouragement at around the same time from his mother to get school supplies (notebooks, pens, and pencils) to practice the writing all the preschool classes were doing that Izuku succumbed to the urge to analyze the quirks he observed in his favorite heroes and his classmates. He started a series of notebooks with the one that he titled, simply, Analysis #1 (to avoid any punishment from his father for his dream to be a hero) . Once Hisashi accidentally learned about Izuku’s new obsession with learning about quirks from a journal left out a second too long, against what Izuku expected from him, he ended up encouraging it, and even begun to bring “exclusive” clips from both villains and heroes for Izuku to analyze — which he did with gusto, consuming the information without thought. (He would figure out in several years where and how Hisashi got these clips and cringe in horror.)
Izuku had a hard time determining why Hisashi was allowing him to analyze and follow a habit so related to heroes and their quirks generally, especially considering how much Hisashi hated heroes, particularly All Might. But he began to suspect something — although he wasn’t sure what exactly — with the video clips Hisashi gave him to “aid” in his analysis when Hisashi told him to analyze the villain’s quirks too.
“After all, who knows how much knowing and being able to analyze a villain’s quirk could help you in the future to analyze a hero's own quirk, right?”
Hishashi’s statement left Izuku confused. First, Hisashi gives Izuku a reminder of what he could and couldn’t say or broach around him in the form of a bracelet of scars. Then second, Hisashi talks and even provides Izuku with more material about the one topic Izuku knows Hisashi hates above all others. Izuku struggled to figure out what he should or shouldn’t be doing, and eventually settled on the compromise of never bringing up heroes unless Hisashi was already talking about them himself, since so far, it had led to the least pain.
Some of Izuku’s first entries into his Analysis #1 notebook were his parents’ quirks. His father’s quirk was something of an enigma, seeing as he gained an emitter ability on top of what is a somewhat typical transformation quirk, albeit a rare one. Hisashi could transform into a dragon, with scales and wings and claws, like Ryukyu, the hero, although this form had far fewer human characteristics whereas Ryukyu retained some of these characteristics. He also could breathe fire, and it didn’t matter if he was in his scaly reptile form for this ability to be used. It was the reason Hisashi had registered his quirk as “fire-breathing”, when in fact it was actually a dragon transformation that caused the emitter ability. Izuku didn’t really know why Hisashi hadn’t just registered his quirk in its entirety, but that topic was quickly snatched from Izuku’s mind of ‘discussion topics’ .
Inko was conversing with Hisashi pleasantly while Izuku ate silently during dinner one day until Hisashi seemed to remember something after he’d given some clips to Izuku for analysis earlier.
“Hey brat,” he called Izuku, interrupting Inko, who fell quiet without a peep in protest, continuing to eat.
Izuku looked at him while leaning back subtly, nodding that Hisashi had gotten his attention.
Hisashi spoke before Izuku could manage to respond verbally. “My quirk is registered as fire-breathing. Don’t you fucking dare tell anyone differently. No teachers, no other parents, no other brats, no one. Or else.” Hisashi’s eyes spelled out the promise of violence if he were to disobey where his words failed to satisfy that particular requirement. “Got it?”
Hisashi glared at Izuku during the two seconds it took for him to register the question and finally to nod frantically. The tension had risen to an insufferable degree within those two seconds, demanding nothing short of compliance of Izuku. He was bewildered by Inko’s lack of reaction to it. He didn’t understand . He decided he really doesn’t like not understanding.
When Izuku learned this detail, the already building suspicion of Hisashi and his intentions began to swell further as he learned this new information. Izuku learned to carefully guard his notebook to prevent any leak of the information, seeing as he had no idea what lengths Hisashi would go to punish him if anyone learned about the quirk not being what it was registered as.
He then created two separate entries for Hisashi’s quirk. One including just a drawing of Hisashi in his human form and his “emitter” fire-breathing ability in the beginning of the notebook. The other wasn't titled by any name, but included a drawing of Hisashi’s fully transformed dragon form and the full analysis of the form’s abilities and weaknesses (though his father never knew these were included, as Izuku feared what consequences that might bring down on him for looking down on him). Izuku made sure to include this analysis near the middle of the notebook, to avoid any similarities being drawn between Hisashi’s (now) two entries. If any classmate wanted to know his father’s quirk, he merely told them fire breathing, and showed them the first entry he had of his father if asked about it, against the feeling in his stomach that resisted the lying.
On the other hand, his mother’s quirk was much easier to explain because he never had to lie about it. He only made one entry on her, and greatly appreciated the lack of secrecy after having to make such a great effort to conceal the true nature of his father’s quirk. He really hated lying. It was a relatively simple weak telekinesis that only allowed her to pull small objects to herself.
It was within this time of learning to read and write and analyzing quirks that Izuku began to wonder what sort of quirk he might develop with his childlike curiosity. He was nearly four, as summer approached with his birthday in tow.
Izuku checked out quirk theory books from the library, and then checked out books on the evolution of quirks, from the history at the dawn of the mutation renamed “quirk” to how quirks are passed down from parent to child. He learned the following information from a book on quirk biology:
“Quirk inheritance patterns generally follow the genetic information that the parents pass on to their offspring. The recombination factor during meiosis in the parents that create the offspring’s zygote can make it so that one grandparent’s quirk factor, or one of two alleles that accounts for the quirk factor in that grandparent that was passed down to the parent, is more dominant in that parent’s gamete. Or the recombination in the parent can combine the quirk factors of both grandparents, as it were, which is usually more likely, so that the offspring is more likely to gain a quirk factor that is usually expressed like their parent’s own quirk. That is how quirk factors from each parent are generally passed onto the child.
“This combination of these quirk factors in the child usually results in one being a more dominant ability than the other. In this situation, one parent’s quirk will be manifested by the child, whereas the other parent’s quirk does not appear at all in the offspring. In rarer cases, the ability could be manifested in a way that is a combination of the parent’s quirks, but there is almost never an even combination split, but rather what looks like a slight variation of one of the parent’s quirks due to the new factor of the other parent. For example, the more dominant fire quirk could become electricity based or a lava based, depending on how the two quirk factors of the parents combined.
“Or, if the dominance of each of the inherited quirk factors are equal, there’s a possibility of a combination of the two original quirks manifesting. Usually they would end up being connected in some way — like needing to be in balance with one another to avoid some sort of backlash for overuse of one side of what is essentially a new quirk over the other side. These cases are extremely rare, as slight or complete dominance of one quirk factor is much more likely in all known cases. There have only been a few cases of these new quirks being created with this kind of equally dominant combination of quirk factors. This phenomenon is called ‘incomplete dominance’.
“There is one more possibility for why a quirk that a child manifests is completely unrelated to the parent(s)’s quirk, and that is the possibility of mutations, although this is essentially the least likely option behind why a quirk is the way it is. It is suggested that the family and family history is checked fully for any related quirks before turning to the possibility of a mutation occurring (see page 132 for an overview of information relating to mutations and how they occur)...”
Izuku’s brain was whirling by the end of the textbook’s page of information. It took looking up certain biology terms, like recombination, gamete, and meiosis, for him to fully understand what all of it meant. Then there was the issue of mutations, which Izuku decided to further research after fully taking in the most common occurrences. Once he understood what they meant, Izuku re-read the entire block of information, that was generally the summary of much more specific information that comprised a large percentage of the textbook. He immediately sat up from his curled- up position within the library and considered the information, gazing at the flat white ceiling.
“So the most likely quirk I am to manifest is either mom’s telekinesis or Hisashi’s transformation, or some strange combination of the two. But there’s also the factor of whether the recombination of my parent’s quirk genes made it so that one of my parents had recombination that included all, if not most, of one of my grandparent’s DNA, which means that I should figure out my grandparents’ quirks and my great-grandparents’ quirks -- if I really want to be thorough, but I doubt that really matters -- by the same reasoning, so that I know what I’m likely to get based on the probabilities of how my grandparent’s genes recombined to make my parents, and the same for my great grandparents… So basically the pattern we see is that quirks tend to skip generations in a decent number of cases, but are more likely to either become something more similar to whatever the parents’ quirk is, and more rarely as a combination, or a slight alteration…” Izuku muttered into the still and tranquil air of the library as he processed the dump of information within the introduction of this quirk biology textbook.
As he continued to think out exactly what he might need to predict his future quirk, seeing as just the knowledge of his parent’s quirks is likely not sufficient to determine any kind of quirk. It’s obvious even at this moment to Izuku that his father’s transformation quirk is vastly more complicated just due to the extra emitter type quirk he can use at any time, and is either much more dominant than his mother’s because of it, or much weaker for all the complex parts within it, or more likely to be combined into something because of all those factors. It appears that even pro hero Ryukyu doesn’t have the level of scaling detail that Hisashi’s transformation has, and Hisashi’s dragon form is much larger than hers, too. And that’s not even mentioning Hisashi’s fire-breathing ability, which Ryukyu has never been seen as having. That makes Hisashi’s version of the quirk factor vastly genetically different from Ryukyu, seeing as some people just have the fire breathing ability as their entire quirk factor, even if it isn’t particularly common in the population.
Izuku suddenly jumped, his thoughts breaking off, when a kind and wrinkled hand gently set down on his shoulder. He looked around wildly, having not noticed his muttering or someone else nearing him as he stared at the textbook without seeing. He found the owner of the hand at last, and relaxed. It was the old lady that ran the check-in and check-out desk.
“Hey, young man,” she murmured quietly and gently, likely having noticed his reaction. “Do you mind quieting down a bit? Libraries are generally meant to be silent, although your thoughts are very insightful and well-formed.” Her lips twitched, as if ready to laugh.
“S-sorry!” Izuku stuttered. Did she just tell him off and compliment him at the same time? “And, um, thank you?”
She chuckled and gently ruffled his hair. “Keep it up, kid… Just, you know, keep it quiet.” Izuku stared up at her with wide, shocked eyes.
She smiled one last time at the look on his face and walked away with a few books to return to the shelves.
Izuku carefully pressed his jaw shut and tightened his lips carefully to stop any more of his thoughts from spewing into sound waves, and carefully gathered up the book he had pulled from the nearby shelf of high school and college level textbooks to walk up to the counter. He wanted to know everything there was to know about quirks and their biological applications. Even if the textbook started with how quirks are passed on, later it covered quirk theory and how quirks could be emitted or even simply manifested in the human body in conjunction with the biology of a normal, quirkless person from before quirk factors manifested in the human species. It was hugely interesting to him, even if his classmates would make fun of him for reading a book that college students would whine about and avoid reading.
But what they didn’t know about couldn’t hurt him — which is why Izuku kept the textbook at home for the next two weeks he had it, carefully note-taking on the information he didn’t expect he would or could instantly absorb.
Hisashi also seemed to be anticipating Izuku’s quirk, seeing as he asked Izuku the same question every day when he woke up and came home from school, starting around the time Izuku brought the textbook home: “Did you get your quirk?”
His answer for the next three months or so was inevitably and invariably, “N-no.”
And the answer only changed after those three months because Hisashi didn’t give him a chance to answer verbally before he decided the quirk needed to be coaxed out by a different means — physically.