Izuku and Katsuki were engaged in a heated game of checkers, Izuku winning (despite him never needing one he still had 30 odd backup strategies that were constantly shifting), when their father walked in.
He still wasn't used to the calm sight of his biological son playing with his adopted son, it was eerie but nice, but once he regained his composure he called out to the boys. "Hey kids, look what came for you today!" He said whilst tossing them a letter each. The boy's eyes widened as they quickly rushed to their respective rooms to read the letter as fast as possible.
The house echoed with Katsuki's excited "FUCK YEAH!" and Izuku's equally ecstatic, if somewhat more restrained, "Yes!". They immediately ran out of their rooms and looked each other dead in the eyes. "1-A" They said in sync. Now was the part they were both waiting for. Katsuki went first. "110," he said, Izuku had a smirk growing on his face.
"111," the green haired boy replied.
Katsuki was steaming but looked his brother dead in the eyes and simply said "Damn nerd."
"OI! Get your assess down here for dinner!" Their mother called them down, "You two have a couple days before school starts, and had better keep good until then!" she continued, as the boys hurried down the stairs. They did not need to piss her off, that would definitely shatter their mood.
It was the day. Their first day of high school. After their mother got a photo, she said it was for memories, but both her children knew it was for blackmail purposes, the two started on their way to school.
It was a short walk and were both ecstatic. At least, that meant Izuku was motor mouthing his curiosity regarding who would be in his class, what would be their quirks, etc (he had made sure to pack at least two notebooks and a couple pens) whereas for Bakugo this meant he was actually occasionally engaging with his brother's energetic tendencies. Izuku did make sure to reel himself in slightly, and by slightly it was closer to marginally, as to not overwhelm his new classmates. Eventually the pair managed to find their way through the giant school and made it to a pair of giant double doors, with a large golden 1-A adorning the top.
They entered the room to be greeted by the blue haired boy from the entrance exam. He immediately recognized them and made his way over. He fixed his glasses, unintentionally intimidating the green haired boy, and began to make some... interesting arm movements as he began addressing the two. "Greetings! I am Iida Tenya! I apologize for my actions on the day of the entrance exam! I severely misjudged your intentions and look forward to establishing a relationship!" he finished with a sharp bow. Bakugo just glared at the boy and made his way to an empty desk, whereas Izuku did his best to calm the boy and began to fanboy slightly. "I'm Izuku! Wait you're an Iida! Are you related to Ingenium? What's your quirk? Do you have engines similar to his? Hey, has anyone ever had engines on the back of their head? That'd be annoying," he excitedly shot off, doing his best to restrain himself, albeit unsuccessful. It wasn't working. He heard his brother yell at him to, quote, "chill the fuck out". Izuku apologized before taking a seat near his brother, leaving Iida in a slight shock.
After a little while, and a lot more greetings, Iida returned to his own seat and began waiting for the teacher. There was still a couple more minutes, but he was unimpressed by their teacher regardless. This was U.A! The top hero school in the country! And yet their teacher was absent! He sighed; he knew this was his best chance to become a hero but there were surely better schools with better teachers than this! He straightened his back further and waited for the bell to ring.
Izuku was slightly embarrassed by his lack of restraint but didn't let it hamper him as he greeted the girl, he had talked to at the exams. He hadn't seen her quirk in action and was really curious as to what it did, with lightning firing throughout his head as he powered his brain and senses. Suddenly, he heard a shuffling at the door as a zombie emerged from a sleeping bag. He jumped, attracting the attention of his classmates who then proceeded to look at what had startled the green haired boy. "4 seconds. Good enough. Right, put on the P.E uniforms and come out to the field." He told them, rather monotonously.
"But sir! Wasn't there meant to be an introductory assembly today!" Iida called out.
"We teachers are allowed to do what we like. Welcome to U.A," The teacher responded, with a grin that can only be described as shit eating, "I'm Aizawa-sensei, and you've got 5 minutes to get changed. If you are late you will be expelled."
It took all of Izuku's self-control to not start fanning over the pro hero, Eraser Head, he was well aware of the hero's... irritable tendencies noticeable in both the limited information regarding the hero, and his few run-ins. Using some of his charge he sped himself up slightly to get out early. He was one of the first out and used his time to charge up a decent amount.
He was by no means nearing capacity, but he still wanted to have enough energy to think (and hopefully keep going for the rest of the day). Eventually everyone made it out, and Aizawa-sensei looked marginally less annoyed (maybe? It's hard to tell) and began explaining that they were going to have a quirk apprehension test, to see their potential. "Hey, this sounds like fun!" A pink skinned girl with horns called out.
"Fun? Well then let's make this more interesting. Lowest score is assumed to have no potential. And thus, will face expulsion, effective immediately." Aizawa-sensei said, a smirk growing on his face. Everyone promptly panicked. His smirk grew wider.
Before the test began, Izuku and his brother looked at each other, each with a challenging glimmer in their eyes. They nodded; a silent challenge agreed upon. They would do their best; winner takes bragging rights. And boy would they use those bragging rights.
Katsuki and Izuku were both prepared to do their best to best the other. Izuku knew that his brother had the upper hand in terms of immediate power, but he had the upper hand in stored power and having power over time. With the first event being a sprint, Izuku easily being faster than his brother being able to channel energy straight to his legs, being able to get 2nd overall (beaten by Iida).
Katsuki was able to best his brother in both long jump and triple jump by using powerful explosions to propel him further (he was first overall in both, his brother getting 3rd after an ice user). Izuku beat him in grip strength (getting 2nd only after someone who had an incredible amount of arms) and he and his brother tied for side jumps (Izuku using general lightning boosts and Katsuki using explosions) and were bested by a boy who continually bounced back and forth between two of his purple hair... things.
The final event was the ball toss, and both knew they couldn't beat Uraraka's infinity score, but could definitely do their best against each other. Katsuki propelled the ball 750 metres with a signature yell of die, and whilst Izuku was preparing to throw his with a combination of raw boosted strength and a plan to use an extended lightning strike when he felt a lack of energy. He panicked and ran as far away as possible despite the teacher's best attempts to restrain him. Then it happened.
Aizawa was fairly happy with his class and was watching carefully when he noticed a certain green haired boy. His name was Izuku and it seemed that throughout the tests he was holding something back. He believed his quirk was green lightning, or something along those lines (he wasn't going to memorise the quirks and details of all 90 odd students he was teaching that year before the year even started). He also noticed an interesting connection between him and that Bakugo kid, they were brothers or something like that. He decided to ignore that for now. Coming to the ball toss, the final event, he saw the green haired kid seemed to be holding an excessive amount of energy whilst using hardly any of it. He decided to confront the kid and activated his quirk. That was when he realised, he made a huge mistake.
Bakugo was watching his brother line up for the ball toss, when he suddenly saw Aizawa-sensei's hair stand on end and his eyes go red. His brother seemed to notice this immediately and moved far away from their classmates when it happened. Bakugo realized what was happened and yelled a desperate warning to their teacher who began to approach his brother, still with his quirk active. That's when it happened. Everyone around the school not only heard, but saw, and some even felt the surge of energy.
Aizawa began to back off as he felt massive pulses of energy, and that's when he heard it. It was a crack of thunder, unlike those heard in thunderstorms. This was different. It was overwhelmingly loud, a noise that Present Mic would be jealous of. He looked back at the green haired boy who was surrounded completely by intense green lightning, firing off in every direction, so much that it was almost a solid beam of light.
He jumped further away when he realized what happened. Erasing the boy's quirk meant that the boy's stored energy was to be all released immediately. The intensity of the energy released was immense, and as soon as it happened it ended. Aizawa was at a bit of a shock before hearing a boy call to him. A third year, Mirio Togata. "Hey Aizawa-sensei!" Mirio called out. Despite how casual he was, the amount of respect he had for the teacher was still clear, "Would you like me to look after your class while you deal with that?"
"Yeah," Aizawa responded, trying to compose himself, "Yeah that'd be great." He could hear Mirio begin to introduce himself to the class, as the other members of the big three also showed up. His class would be in good hands. Right now, he had to deal with whatever just happened. He tenderly picked up the boy, who was incredibly worse for wear.
The green haired boy was twitchy, covered in burns and unconscious. That wasn't too surprising considering the immense amount of energy that just came out, all as lightning (watch was fast, and being so fast it made it incredibly hot). He could still feel the warmth on the boy's skin as he carried them to Recovery Girl.
Bakugo could smell burning flesh as their teacher ran past, his brother cradled in his arms. He wanted to go and find out what was going on when he felt tentacles grab him. "Yo what the fuck is this! I swear to god, whichever one of you fucking extras this is I will blast you limb from limb if you don't let go!" He screamed, to no avail. "Woah woah woah, chill dude. They'll take care of that kid no worries," Kirishima told him in an attempt to calm the explosive blonde.
"He's right," a cartoonish boy said, "Anyway, I'm Mirio Togata, and I'll be watching over you guys until Aizawa-sensei returns."
"Then who are those guys?" asked a girl with long black hair. Her name was Yaoyorozu or something like that.
"We are part of the big three!" a girl with long blue hair responded, "I am Nejire Hado!"
"And I am Tamaki Amajiki..." a shy boy, the one with the tentacles for hands trailed off. Bakugo had stopped struggling long ago but had also stopped listening as he zoned out, concerned for his brother. He knew that teacher's quirk had done something to erase his brother's quirk (Bakugo would never admit it but he had actually paid attention to some of Izuku's ramblings), and it seemed as though all the energy Izuku had stored up before hand was all released at once, with no quirk to control the excessive amounts of energy stored within him it immediately released.
Suddenly the girl with blue hair, who had up until now been bombarding various different classmates with questions, turned her gaze towards him. "Heyyyyy, I think I know you from somewhere!" She said.
Bakugo simply shrugged and tried to ignore her but she still continued, "Hey what's your quirk? What happened to the boy that just left? What was his quirk? Was that his quirk? I saw a brief flash of green, did that have something to do with it?" Bakugo was prepared to respond, his brother's ramblings were somehow harder to keep up with than this girl's questioning, when Mirio cut her off. He continued talking, about something but he couldn't help but notice he wasn't the only one distracted.
The hyperactive blue haired girl was also lost in thought, which the shy boy also noticed but didn't say anything about. It seemed Mirio also noticed this, with the occasional glance at her but he kept his focus on the class until their teacher came back. What a first lesson.
Izuku could feel warmth all over his body, as though he was just roasted over a spit, yet he couldn't actually feel anything. His nerves were probably fried after that. There would be no shortage of scars from this.
He groaned as he turned over, he knows he should be feeling pain, but he also knew that was probably a result of the sudden outburst of lightning from him as his nerves would be somewhat out of action for a little while. "Ah good, you're finally awake. Don't try and move, just lie there and I'll make sure you get your work once you're feeling better," a voice spoke, he turned to see where it originated from. It seemed to have come from a short, elderly looking lady with an oversized syringe as a cane.
Recovery girl. Normally he would've started freaking out over her, but his energy was literally all gone, and didn't bother making a sound. This seemed to please the elderly nurse as she explained that she wouldn't be able to heal him until his energy was back, and as a result he needed to spend his time resting. Izuku mumbled something incoherent back, before drifting back into the sweet abyss of sleep.
The class continued in an eerie silence, by the time Aizawa had returned he knew that there would be a slight glumness, but not to this extent. The big three were doing their best to keep the mood light, well, Mirio was. Nejire was lost in thought and surprisingly quiet, whereas Tamaki was silent, as usual. Aizawa pinched his nose bridge, maybe there was a connection between the problem children, but he couldn't be bothered to figure it out right now.
Clearing his throat and making his presence known, he thanked the big three for their help and told them that they could return to class. What he didn't expect, was Bakugo to speak up. "Oi! Can I go visit Izuku now?!" Bakugo yelled in a typical abrasive voice, although there was a hint of concern and worry in amongst it.
Aizawa sighed, "You can go visit your friend come lunch, right now you need to focus on maths." Aizawa's response was met with a tsk, and a grunt of compliance. At least he hoped it was compliance. He turned back to the board and started writing up some equations, a smirk growing on his face. "Alright, who is excited for some trigonometry?"
Mirio and Tamaki did their best to contain the curiosity of their best friend, as she was eager to learn more about the boy who had just let out one of the most powerful blasts of energy any of them had heard, seen, and felt.
It was a green strike, which seemed strikingly familiar to them in a way none of them could quite place. Nejire felt like she vaguely recognised the quirk but didn't get a chance to get a good look at the boy before he was carried away rather hurriedly, by Aizawa-sensei. It was fair enough, his body was twitching and looked like it was covered in burns. Like, literally covered with burns. There was not a single spot on his body that was not charred, and she could feel the heat being emitted from the poor boy as the teacher ran past.
Eventually she gave in, telling her friends that she wouldn't bother the boy. Probably. Maybe some other time. Definitely some other time.
By the time lunch came around, Bakugo was itching to go check on his brother, and the moment the bell rang he had run out of the room and headed straight to the nurse's office. He was very worried, more so when Recovery Girl told him that Izuku was still asleep, and probably wouldn't be awake until closer to the end of the day. He sighed, whispered some of his unique encouragement in his brother's ear, and returned back to the cafeteria.
Eventually he found the rest of his classmates, who were sitting together at a table. He sat next to Kirishima and didn't really say much other than the occasional cuss when someone talked to him. By the time they had final class, which was English with Present Mic, Bakugo was too nervous about his brother to really pay attention. Whenever he was asked a question he did answer, just with slightly more... colour than usual.
Not too long before school was about to finish, the classroom door opened, attracting everyone's attention. There stood Izuku, exhausted and nervous as ever for disturbing the class. He quietly took his seat and started writing his notes, although slightly less than normal (still excessively more than anyone else though).
Eventually, at the end of the class, Present Mic gave the students some time to socialize and most attention was directed towards Izuku, the poor anxious green haired boy. He was way too tired for this, and his brother knew that, but his brother was also so loving that he wanted to see Izuku suffer. Sure, he would pay for it later, but right now he just wanted to see this play out. Everyone wanted to know what had happened. "O-o-oh, uhm..." Izuku trailed off, "I guess first you need to understand my quirk. Basically, I can charge and store a green lightning, which can be used for enhancement or as a long-ranged attack, not really sure what the limits are yet."
"So is it like my electrification?" Kaminari asked, curious if he had a fellow electricity user.
"In a way, but it is far more versatile," Izuku continued, "the issue is that I can't generate it quickly, hence I need to charge it up. But the main problem that happened was when Aizawa-sensei erased my quirk, my body had all the energy stored up, but without the quirk it had no way to control it."
"So that means, it expelled itself as fast as possible from your body?" Yaoyorozu asked, a thoughtful expression on her face.
"Y-y-yeah, pretty much." Izuku finished, his nervousness returning.
"Are you okay now?" Uraraka asked him, concerned for her first friend at the new school.
"Y-y-yeah, I just ended up with burns and some temporary nerve damage, n-n-nothing too bad," He replied nervously, desperate for the attention to end. Luckily for him, it did, and Bakugo watched as his brother returned to his seat, focusing on the notes from the lesson.
By the end of the day, Izuku was still on his feet, only barely though. Anymore interaction and he would probably just collapse into a puddle. Unfortunately for him, that's what was going to happen.
The third years he recognised as those from in front of the gate came up to him, but before he could get a word out, he just fell asleep. Luckily, his brother was there to catch him. They told him that Izuku was exhausted after what happened earlier and would be alright later. Bakugo heaved his brother onto his back and started on their way home. The third-year boys understood and started heading away to meet up with their other friend, and make sure she didn't bother the exhausted green haired boy, who was being carried away.