My Teacher Is My Dad?!

Rated: Teen for language, violence, slight romance.

Summary: Midoriya Izuku starts a new phase of his life by attending U.A. High. But many obstacles still stand in his way, like a quirk that is still too much for his body to handle, a class full of students who would just die to discover that Izuku is All Might's son, and… villain attacks?!

Disclaimer: My Hero Academia is owned by Kohei Horikoshi.

LES: Well, here it is! The sequel to My Hero Is My Dad?! And in case you did not read the last story, here's just a few things…

1. This is a biological Dad Might story. That means that All Might/Yagi Toshinori is Izuku's actual father. Toshinori and Inko were friends that had a drunken one night stand, and the result was Izuku. Toshinori and Inko are not in a relationship, but they are both committed to being Izuku's parents, especially since All Might came back to Japan.

2. Izuku received One For All several months before he did in canon, and he had more time to train for its use. However, in order to keep Izuku from being too overpowered and breaking the story, Izuku can still only use a percentage of One For All without breaking his body, but he is up to 20% and can use Full Cowling thanks to Gran Torino knocking some sense into Toshinori and Izuku early. I also made up some fuzzy math that would make any math teacher want to murder you in order to up the power of Full Cowling and to get around the "He's using more than 100% of his full power!" BS that often comes up in canon. (Basically, when One For All is spread throughout the body, certain percentages of the total power is stored in separate parts of the body. Like with All Might, he almost never attacks with 100 percent of his power. That is basically the United States of Smash. Most of his attacks are only about 30 to 40 percent of his total power. And since he almost never goes above that, people think that's his ceiling. So when he does push himself to higher levels of strength, people watching think he's using more than 100 percent of his power, when is actually probably using closer to 100 percent than he was before.)

3. Early on, Izuku was taken out of public schooling and put into private schools, the same ones as Iida Tenya and Yaoyorozu Momo. These three became friends. Iida and Momo had always known that Izuku was the child of a high ranking hero, but they didn't know who and they had no idea what his quirk was thanks to Izuku not having one for several years, and then keeping his quirk a secret after he did get it. However, after the practical entrance exam, Izuku finally revealed a simplistic version of what his quirk is, Iida and Yaoyorozu put together that Izuku is All Might's son, and now they know the secret of his parentage. Oh, and they are all on given-name terms now.

4. After Izuku was taken out of public school, he no longer had to deal with Bakugou and, most importantly, bullying about being quirkless, since all the students just assumed that he had a quirk but was keeping it hidden. Thus, this Izuku is a little more self-assured when it comes to Bakugou than in canon. And their relationship will absolutely not be the same as it was in canon. Bakugou all ready told Izuku not to call him "Kacchan", and Izuku will put his foot down in turn about the whole Deku thing. Bakugou is a slightly different person as well. Oh, he's still mouthy and abrasive, but he's not as physically threatening as he is in canon. He'll yell and curse out the other students and he is still mostly a mass of walking talking pride, but almost never attacks physically. Izuku was the source of most of his rage and without Izuku clinging to him, he is just slightly better.

5. Speaking of Deku, Izuku has no feelings for the name at all. As far as he's concerned, it's a just a shameful childhood nickname that he would just as soon leave in the past. After an unofficial poll from my reviewers, the new choice of Izuku's hero name will be Dekiru, which is the Japanese phrase meaning "You can do it!" Japanese dub listeners will recognize it as the word Uraraka uses to compare with the word Deku and why she thinks Deku would be a good hero name. In this story's case, Izuku will just be Dekiru would be a good hero name, definitely not use the fact that Deku sounds like Dekiru to justify taking Deku as a hero name.

6. Due to having Izuku and Inko looking out for his health, Toshinori is slightly healthier than he is in canon. He is still horrifically skinny, simply because his muscle form uses so many calories that his stomach-less body can't possibly keep up. His time limit is still around three hours, but he is a little less prone to coughing blood attacks.

And… I think that's everything for the last story. Now… on to the current story!

ACT 1: YEAR ONE

Chapter 1

The time between Izuku's acceptance into U.A. and his first day of school seemed to pass in the blink of an eye, but that did not mean that Izuku had started to slack in his training.

Late in the evening after delivering the good news to his son, Toshinori had briefly pulled his son aside. "I couldn't be more proud of you for being accepted into U.A. But you do know that this by no means guarantees that you'll be a top hero."

Izuku nodded. Just because all of Japan's top heroes have come from U.A. doesn't mean that every person who gets accepted into the U.A. hero course becomes an automatic success. Getting accepted was just the first step, and it was only an uphill climb from that moment.

"I also feel like I should give you fair warning..." Toshinori said. "There are two teachers taking on first year homeroom classes for the hero course this year. If you end up in Vlad King's class, you don't have a lot to worry about. He's very tough and he's excellent at pushing students to their physical limits, but he's overall a mellow teacher. However, I do have to give you a warning in case you end up in Eraserhead's class."

"Eraserhead? I actually don't know that much about him, besides having seen him a couple of times at the U.A. campus." Izuku commented.

"You wouldn't know much about him. He's an underground hero and prefers to stay out of the limelight. Just because he's unknown and not highly ranked shouldn't fool you. He's great at what he does. He gets the job done, and he does it well. I've heard that he even willing to form contacts among the vigilantes if that is what getting the job done requires." Toshinori said casually, as if vigilantism were not highly illegal in Japan. Again, it was probably his years in America speaking. "But you must know, Izuku, if you end up in his class you'll have to work very hard. Eraserhead has a record of producing the classes with the highest rate of people who become successful pro heroes rather than getting sidelined as a sidekick. However, that is mainly due to his habit of expelling those students that he finds to be unworthy."

Izuku looked a little nervous at that statement, but then his face hardened with determination and he met his father's gaze. "If I wanted to find an easy hero program to coast through, there are hundreds of different hero courses throughout the country. I all ready know that I will have to push myself in the U.A. hero course. Plus Ultra, right?"

Once again, Toshinori was impressed with his son's drive. Possibly having an intimidating teacher would be a high obstacle to some people. But Midoriya Izuku was far too driven by his goal of being the best hero in the world to let a little thing like a difficult teacher stop him.

"If you end up having Eraserhead as a teacher, just show him the hero's heart that you have shown me these last several years. Show him that your relative lack of control over your quirk is not as big a hindrance as he thinks it is. Show him that you are willing to work even harder than everyone else. He will see your potential just as I have." Toshinori told Izuku. "But, if you end up with Vlad King you don't have to worry so much..."

"No." Izuku said firmly. "I understand what you are saying. Eraserhead all ready said something about me, didn't he?"

Toshinori hesitated before answering. "He was… not as impressed with the feat with the robot as the others. He thinks that the fact that you hurt yourself with your own quirk is a sign that you have not put any effort into learning how to control it."

"But that's not true at all!" Izuku said. "Sure, I can't go all out, but I'm good at limiting myself properly. But I couldn't limit myself in that moment because I needed all of my power to destroy that robot."

"I know." Toshinori assured his son. "I know you very well, Izuku. But Aizawa does not know you like I do. He thinks I'm a bit of a show-off and, as my son, you are too. Now, I can admit… I like the attention, so he's not wrong about me. Just show him he's wrong about you."

Izuku nodded. "I'm not afraid of getting him as my teacher." He said. "Sure, there's a higher risk of getting expelled if you don't meet his expectations, but there is also the greater reward at the end. If his mentor-ship results in better heroes, then that is the class I want to be in, difficult or not."

Toshinori nodded, pleased. If Izuku could show these exact qualities to Aizawa, it would be the proof he needed that Izuku was not lazy. Aizawa was tough, strict, and expelled students at a higher rate than any other teacher, but if he did see your potential he would work tirelessly to mold you into a fine hero.

He knew that he would have very little to worry about if Izuku did end up in Aizawa's class. But, still, the tiny little nugget of worry managed to lodge itself in his chest. He could… keep an eye on Izuku during his first days, just to make sure that he was settling in.

So the time passed, and before anyone knew it, the new school year had begun and Izuku dressed himself in his new school uniform. His mother gave him a big hug and told him how proud she was of him before he stepped out the door. He took the train a couple of stops until he arrived at the platform that serviced U.A. A couple of other U.A. students also got off the train with him.

Izuku blushed a little when a young boy pointed at him and the rest of the U.A. students as his mother was leading him onto the train. "Wow, Mommy, look! U.A. students! Are they all future heroes?"

"Some of them will be." The mother answered.

It was almost impossible to tell U.A. hero course students apart from students of the other three major departments: General, Support, and Business.

It was just a short walk up the road to the U.A. campus, and from here it became easier to start telling students apart, at least by year. While the first years seemed to be equal parts nervous and excited, the upperclassmen were hanging around within their friend groups, chatting to each other about their end of year break.

Izuku walked passed the U.A. barrier, which recognized his school ID and let him pass. Past the courtyard was the building itself. The front entrance had three doors, which led to the small anterooms for each of the three years. There were lockers for students to drop off their personal items, and also boxes for umbrellas for when it rained. Izuku did not have anything to drop off this morning, so after finding his locker for future reference, he walked into the hallways of the building proper.

The second and third year students took a quick glance at their classroom assignments before they turned and walked away with the confidence of knowing the school's layout. But the first years were a little more nervous and lost. Izuku looked down at the paper he'd been given with his class assignment. His homeroom was to be classroom 1-A.

Without any better ideas since all of the upperclassmen had walked off, Izuku set off down a hallway at random. He had been on the campus a few times, but other than the entrance exam, the only place he had gone to was the nurse's office. And he had not remembered seeing a classroom 1-A in the areas that he had been. So he took a direction that he had not gone before.

At first, he got a little worried before he found the General and Support classrooms first, but at least he was in the first year area, so he knew that he was in the right general area. Finally, after a few more minutes, he arrived at the classroom marked as 1-A.

1-B was right next door, and the only other Hero Course classroom for first years. There were only two hero course classes per year, and by far the smallest course in the school. Forty hero course students in total. Four of those students would have gotten in on recommendation, two per classroom. While thirty-six got in through the normal entrance exam.

Like all of the doors at U.A., the door to the classroom was massive. In fact, the whole school was massive because it had to be built with people with large quirks in mind. Not all people were like Mount Lady who could change size at will. Some people were stuck being very large.

Izuku hesitated a moment before he stepped into the classroom. Inside this room were his fellow hero course students, and all of them would be the best and brightest that Japan had to offer. These teenagers would be just as powerful and as driven as he was, and competition was soon to be inevitable.

He also had no idea which students would be in this class, or if either of his friends would be there. Tenya and Momo could be in class 1-B right now, for all he knew, leaving him facing a whole new class of people that he didn't know.

And then he realized that he forgot one thing… Ka… Bakugou. It would take him a while to learn to call Bakugou by his family name as Bakugou had demanded of him at the entrance exam, but a part of Izuku did understand. Given names were for friends and people who knew each other very well. Izuku may have been on given name terms with Bakugou when they were children, but it had been years since they had seen each other. If Bakugou wanted Izuku to stop calling him by a childhood nickname, then he would respect Bakugou's wishes.

But speaking of Bakugou, if he were anything like they were as children, he was sure that he would have passed. He may have been a bully, but he was very smart, and his quirk was really strong. Bakugou would have made it into the hero course for sure, but would he be in this classroom, or the next one?

Izuku took a deep breath and opened the door.

There was good news and bad news.

The good news was that he saw that Tenya and Momo were both in this classroom. Momo was sitting in her desk near the back, getting her supplies organized. But Tenya… he was currently yelling at the bad news, who was sitting on top of one of the desks.

"What is wrong with you?" Tenya demanded of Bakugou. "It's only the first day of school and you are all ready disrespecting school property!"

"Eh?" Bakugou brushed off Tenya's yells. "Tell me, did your old school put that fuckin' stick up your ass or is that just your personality?"

Tenya's mouth dropped open at the insult. It just wasn't something that he was used to. After a second, he shut his mouth and stood up straighter, more polite. "I… believe we may have gotten off on the wrong foot. My name is Iida Tenya from the Somei Private Academy..."

Bakugou's mouth formed into a sneer. "Somei, huh? So, what, you think that because we went to some high and mighty private school that you're better than me?"

"No!" Tenya gasped. "That's not it at..."

But then Bakugou's eyes slipped past Tenya and found Izuku standing at the classroom doorway. His eyes narrowed even further from dislike to outright hatred. "Deku." He growled.

Tenya, who seemed glad to have the excuse to step away from Bakugou, turned and made his way back up to the front of the classroom to greet his friend. "Ah, Izuku, did you have a good break?" He asked.

"Yes, I did." Izuku answered. "And how was your break, Tenya?"

"It was great! My brother took me out to eat to celebrate getting accepted into U.A." Tenya said happily. Tenya's brother, who was the hero Ingenium, was an extremely busy hero who ran an agency with far more sidekicks than most heroes took on, so he was almost always busy with his work. That he took the time off to treat his younger brother to a meal spoke of how highly he was proud of his younger brother.

"That's great."

"Are you from Somei too?" Another student stood up from his seat and came to meet Izuku. He was a young man with vibrant red hair and a small scar on his eyelid. He stuck out his hand to shake Izuku's hand.

"Yes." Izuku answered, shaking his hand. "I'm Midoriya Izuku. It's very nice to meet you."

"Midoriya!" Some of the students gasped. When all of the students received their acceptances into U.A., they had been given only their scores. Since then, the scores for the practical exam had become public knowledge to the students. Any student could look up the final scores for every other student. And those students who had looked up that information knew that Izuku had won the top score in the practical exam. Mostly from his crazy amount of rescue points rocketing up nearly to the top on their own. Bakugou had been in second place. He had a highly respectable villain score of seventy points, but absolutely no rescue points.

The red-haired boy stared at him for a moment. He had probably seen the scores. But then he smiled and clapped Izuku on the shoulder. "So you are the top scorer, huh? Good job. I have no idea what you did to get so many rescue points, but it obviously worked out for you. Oh, by the way, I am Kirishima Eijiro."

"That's almost everyone..." A girl who greatly resembled a frog said.

"Just one more person and we'll have the full class of twenty." Kirishima said.

"Oh, wow! You're the boy who saved me!" A voice said behind Izuku, and he spun around. It was the nice girl again! For a second, Izuku couldn't help but stare as she began to ramble about how amazing the his punch against the zero pointer had been. Oh, wow… that uniform looks good on her...Izuku thought to himself, before he shook his head to clear the thought.

"Oh, yeah. Hi! I'm glad you're all right." Izuku said.

"Oh, yeah, I don't think I ever introduced myself! I'm Uraraka Ochaco! It's nice to meet you!"

"It's nice to meet you too. I'm..." Izuku began before another voice interrupted them from behind in the hallway.

"If you just came here to make friends you can pack your things now."

Izuku, Tenya, Uraraka, and Kirishima all froze. Izuku leaned around Uraraka and saw… a human-sized larva with a human face laying on the floor of the hallway. Or, rather, it was an adult male in a bright yellow sleeping bag.

Possibly their teacher, or at least some authority figure.

All four of the students rushed to their seats. It was assigned seating, which had been given to each student with their classroom assignment. As quickly as possible, Izuku counted rows until he spotted his seat. Four rows over and third seat back. Izuku barely noticed that Bakugou happened to be in the seat right in front of his, while Momo was at the back of his row. Tenya was all the way across the room in the first row, second seat from the back with the nice girl sitting behind him. About ten seconds later, all of the students were seated quietly.

The larva man stood up while still inside his sleeping bag. "It took eight seconds for you to get to your seats and be quiet. That's not going to work at all. Rational students would know better." He stepped outside of his sleeping bag and Izuku instantly knew who he was.

Aizawa Shota, AKA Eraserhead. His father's worries had come true. Apparently Eraserhead was going to be his homeroom teacher after all. But Izuku was not afraid. He just needed to prove himself to this difficult teacher and he would be in a good place to get the best training possible.

Eraserhead was wearing his rather drab and unassuming pro hero costume. It was made to not stand out much in anyway, and was made of dark fabrics to help him blend into shadows while he did most of his hero work at night. The scarf that he wore around his neck was actually a capture weapon of some sort. Izuku had no idea how it worked, but it helped supplement his quirk. His quirk, Erasure, could erase the quirk of anyone he looked at. Other than being unable to erase mutation-style quirks, Izuku had no idea of any other limitations the quirk might have.

"I'm Aizawa Shota, your homeroom teacher." He stood at the front of the classroom, glanced over each of them briefly before he spoke again. "Right. We have a lot to do. You have all received your gym uniform, right? Put it on and meet me outside."

Uraraka nervously raised her hand. "Um… sir… aren't we supposed to be going to orientation today?"

Aizawa met her eyes with a level gaze until she couldn't meet his eyes anymore. "The orientation is nothing more than speeches, and a waste of time. U.A. doesn't follow the normal curriculum, which means that I have permission to run my class however I want. We only have three years to turn you into pro heroes, and we can't afford to let even a moment go to waste. Now, follow me to the locker rooms, change into your gym clothes, and meet me outside."

Izuku clenched his fists. His father was not lying at all when he said that Aizawa would be one tough teacher. But, like he told his father in return, he was not afraid. Aizawa was known for weeding out those who he felt had no potential, but that was matched with his reputation of creating strong heroes among those he found worthy.

No matter what it took, Izuku would prove to him that he is worthy.

LES: As I'm sure you can tell from the title of the act, this story is going to be much bigger than the first story. For reference, the manga is on chapter 227 and we are still in the first school year. Nearing the end of it, sure, but still. And since this story is so much bigger, I'm going to schedule regular breaks to avoid burn out. For every time I post a chapter that ends in the number 0, I'll take a week long break. Basically, every 10 chapters. But, hey, you are probably looking at a story that going to keep me busy for a couple of years, at least! So, hey, let's enjoy the ride together!