It had only been a week since the USJ attack, but classes had already gone back to normal. Well, as normal as classes could be at a school for superheroes, Izuku Midoriya mused to himself. Only a few things were unusual.

Mr. Aizawa was still completely covered in bandages and there was something going on outside on the practice field.

The sound of an explosion made Izuku jump.

The boy pressed against the window, trying to see what was going on. Some of the other students stood up to get a better view.

"Huh? Who are they? Do you recognize them, Mr. Aizawa?" Jiro asked, turning to their homeroom teacher.

"That is class 1-Z," Mr. Aizawa answered boredly.

"Class 1-Z?"

"I didn't think there was a class 1-Z."

"I've never heard of it."

The chatter stopped as Aizawa glared at the students.

"If you want me to explain, then you need to be quiet," he said angrily. The students who had been talking shrank a little under his gaze and everyone sat down again. Seemingly satisfied, Mr. Aizawa continued, "Class 1-Z is a special class at UA for students who have extremely dangerous quirks that they can't control without serious training."

"That's scary. And they're in our school? Isn't that dangerous?" Ashido piped up anxiously.

"That's why they're in a different class."

"But why have them here at all? Wouldn't it be safer to just… I don't know, not accept them into the school?"

Mr. Aizawa sighed, leaning back against the wall.

"Just think for a second. If they weren't here, where would they go? What would become of them? You are all very lucky to be blessed with the useful quirks you have, but most of the populous have small, benign quirks that don't do much aside from make everyday tasks easier. Then there are the people who have destructive quirks, or quirks they can't control. You become heroes. What do you think happens to them?"

"Villains," Izuku muttered to himself.

"What was that, Midoriya?"

"Ah," Izuku stood up. "I said they become villains."

"Precisely." Mr. Aizawa swept his gaze across the class. "Let this be a learning opportunity: the only thing that truly separates us from villains, is how we use our quirks. Whether we use them to help people, or hurt them. Class dismissed."

The Pro Hero got up to leave but stopped at the door.

"Oh, and if I find any of you messing with class Z, I'll expel you for their safety and yours."

The students flinched as the classroom door closed a bit forcefully.

"Well that was… weird…" Kaminari said, breaking the silence.

A loud rubble made Izuku look out the window again. A plume of dust rose into the air, hiding the training grounds from view.

"Tch, what a nuisance," Kacchan grumbled, standing up and stalking to the door.

"Hey, remember what Mr. Aizawa said," Kirishima warned. Kacchan paused.

"I wouldn't waste my time."

Izuku watched as the boy left, feeling somewhat worried. After a speech like the one Mr. Aizawa gave them, most would drop it, but Kacchan might see it as a challenge.

"I wouldn't worry about Bakugo," Todoroki said from behind him.

"Oh, I wasn't really that worried, I'm sure even Kacchan knows how serious Mr. Aizawa is-" Izuku rambled.

"Bakugo can take care of himself. You should be more worried about yourself," the boy said cryptically before walking away.

Izuku stared after him, confused.

"What was that all about?"

\\\

"Did you guys catch the news last night? Apparently a few villains broke out of jail and the police can't find them," Uraraka said excitedly, practically ignoring the box of food in front of her. "Do you think they'll ask the Pros to help catch them?"

Iida politely finished chewing and swallowed before replying.

"It probably depends on who the villains are. I didn't recognize them, myself."

They looked at Izuku, waiting for an explanation.

"Well, it's technically the police's job to hunt them down, unless the villains cause problems with their quirks again or the police specifically ask the Pros for help," he replied tentatively. Izuku tapped his chin, thinking. "I can't remember who brought them in to begin with. They aren't big name villains or even super powerful ones, just small time thieves if I remember correctly."

"Hey guys!"

Izuku looked up to see a boy with blue hair and dark eyes, holding a tray. Izuku looked at Iida and Uraraka who shrugged, just as lost as he was. He looked up at the boy again, meeting his dark eyes. Did he know-

"Oh! Sasaki! Here, why don't you sit with us?" He asked, moving down one chair to leave an open seat for his friend.

"Thanks!" Sasaki beamed, setting down his tray.

"It's been a while, hasn't it?" Uraraka asked with a smile.

"Yeah, well, I've been busy," the boy answered, playing with his food. He looked up with a big smile. "But let's not dwell on the past. Let's just enjoy each others company."

Iida nodded heartily in agreement.

"Yes. It's better to live in the present than dwell on the past."

Izuku grinned at Sasaki. It really had been a while… Hadn't it? Sasaki met his gaze and cocked his head slightly.

"Something wrong, Midoriya?"

Now he remembered. They had sat together for lunch just last week. That had been the last time he saw Sasaki. Only a week? It felt longer.

"So what were you guys talking about?"

Izuku paused, racking his brain for an answer.

"Huh? Oh… that's weird, I don't remember," Uraraka murmured.

"Something about the villain break out, right?" Sasaki asked.

Izuku jumped as someone slammed their hands down on the table. It was Kacchan and he looked angry.

"Who the heck are you?" He demanded, glaring at Sasaki. Sasaki smirked.

"Bakugo, don't you remember Sasak-" Uraraka paused looking confused. She turned to look at Sasaki, who was still smirking at Kacchan. "Wait, who are you? I don't-"

The boy chuckled and stood up, taking his tray with him.

"Well, I guess it's over. I had fun while it lasted. Thanks from Class 1-Z for letting me eat with you guys," he said with a sweeping bow.

"Class 1-Z?" Izuku felt his stomach churn a bit. This boy was one of the students Mr. Aizawa had told them to stay away from. But Sasaki was their friend. How had he not known he was in Class Z?

Izuku glanced from Sasaki to Kacchan, then around the table. Iida and Uraraka looked just as confused as him. Then something snapped back into place.

"Wait, I don't remember you at all!" Iida exclaimed, standing up.

"That's a shame. I guess this conversation never happened then. I'll be going now," The boy answered nonchalantly, before turning and sauntering across the lunchroom to where a girl with long blonde hair was glaring at him angrily.

"Sasaki, what were you doing? You know we aren't supposed to-"

"Yeah, yeah, I got it. Thanks, Kurokawa," the boy cut her off.

Izuku turned back to his table and blinked at his friends.

"What- just happened?"

"You idiots got played. Maybe next time I'll just let them keep messing with you and see if Mr. Aizawa expels you for being so stupid." Kacchan taunted, walking away from the table. Izuku glared after him for a few seconds before looking back at Iida and Uraraka.

"Do you remember that guy at all?" They shook their heads.

Izuku sighed and looked away, thinking about the encounter. That boy, Sasaki, had pretended to be their friend and they had believed him. It must have been his quirk or something. But still… There was something about the way the boy had smiled and talked with them that felt genuine.

Izuku shook off the thoughts. He would have time to go into that later, but at the moment he needed to eat before he had to go back to class. He could find Sasaki later and get some answers then.

After lunch they all returning to their class for homeroom.

"Do you think we should tell Mr. Aizawa about the boy at lunch?" Uraraka asked quietly.

"It would be the responsible thing to do," Iida replied seriously. "We should probably report it, so he can be corrected for his misconduct. Such an incident is unacceptable for a UA student."

Izuku didn't say anything as he walked to his desk on the opposite side of the room from his two friends. Mr. Aizawa probably wouldn't punish them for the incident, but the experience had shaken something inside him. To know that someone could trick them so easily was almost scary.

Instinctively, Izuku pulled out his notebook and flipped to a new page. He stared at it for a second before picking up his pencil and beginning to write.

It was some sort of illusion or memory or hypnotism quirk. He had actually thought he remembered Sasaki, despite never meeting him before. And it hadn't only been him. The boy had managed to trick all three of them at the same time. How did it work? Could he use his quirk on an infinite number of people or only a few? Did it all have to be at once, or could he use it on multiple people at different times? What was his quirk?

Izuku looked down at the meager notes, quickly becoming a list of questions he couldn't answer.

"Hello class." He almost jumped as Mr. Aizawa spoke, shuffling to the front of the classroom.

Izuku glanced at Iida, whose face was set with determination. The boy planted his hands on his desk, ready to stand up as soon as Mr. Aizawa dismissed them.

"Alright, it looks like everyone's here," the teacher began, tiredly.

The class looked up as a knock sounded on the door. Izuku glanced back at Iida, who was still sitting in his chair, looking a little startled. Mr. Aizawa sighed, slowly walking over and sliding it open.

"Yes? What do you need?" The teacher demanded gruffly.

"Sorry to interrupt, but there was an incident at lunch between some of our students. I brought Sasaki to apologize." Another voice answered. Izuku strained to see who it was. Another Homeroom Teacher maybe?

The boy stiffened as Mr. Aizawa turned his head slowly, pinning him with a look through the bandages that covered his face.

"Do you know which students?" The teacher turned back to the visitors behind the door.

"Sasaki?" The other voice asked quietly.

"Midoriya, Iida, and Uraraka," A familiar voice answered, just as quietly. Mr. Aizawa sighed tiredly and turned to address the students.

"Alright you three. Come on," he said, gesturing to the hallway.

Izuku stood up, his eyes flicking to Iida and Uraraka who looked just as nervous as he felt. He could feel the entire class's eyes on him as he walked to the door stiffly, following his two friends. In the doorway stood Sasaki and a taller man with a blonde crew cut and blue eyes.

The taller man led them a little further into the hallway and Mr. Aizawa closed the door to the room behind them.

"Are we going to get in trouble for what happened at lunch?" Uraraka whispered to Izuku.

"I don't know, it wasn't really our fault," he whispered back. Mr. Aizawa had said he would expel anyone who messed with Class Z, but he hadn't said anything about what would happen if Class Z messed with them.

The other teacher didn't seem mad at them, in fact he seemed really nice. Familiar even. Izuku wracked his brain for a name.

"Students. My name is Juro Yoshida, though you'd probably know me better as-"

"You're Gravity! The Heavy Hero!" Izuku exclaimed without thinking as it finally clicked. Mr. Yoshida blinked at him before giving Mr. Aizawa a smile.

"Yeah, you know your stuff, kiddo," he said with a chuckle. "And you guys already met Sasaki here." The Pro Hero put a hand on the boy's head. Sasaki looked at the floor solemnly, refusing to meet their gaze.

"Yes, we have met," Iida said stiffly. He was probably still smarting about being tricked, but honestly, Izuku was too. Mr. Yoshida nodded grimly.

"What happened, exactly?" Mr. Aizawa demanded, pinning the other man with a dark look.

"Well, apparently Sasaki used his quirk to make these three think they knew him during lunch today. From what Kurokawa told me, it didn't last very long, but the fact still stands that he used his quirk on them," the Pro Hero explained. "I brought him here so that he could properly apologize." He looked down at the boy expectantly.

Sasaki kept his eyes glued to the floor with a pained expression.

"I'm sorry for tricking you. I shouldn't use my quirk like that," the boy said, bowing. His teacher nodded, seeming to be satisfied.

Izuku smiled at Sasaki.

"Well, there was no harm done, so it's alright," Izuku reassured him.

"No, it's not," Mr. Yoshida cut in gruffly. "And Sasaki knows that. Breaking the rules is still breaking the rules, no matter who's in agreement. Especially when you're putting people in danger."

"R-right. Sorry," he answered, looking down at his shoes. A rough hand tousled his hair and he looked up at Mr. Yoshida.

"It's alright, kiddo. You didn't do anything wrong. But I expect you take that to heart. There are a lot of lines we have to follow as heroes, no matter what's happening. So keep your chin up, and keep moving forward. I'm sure you'll all do fine." The man gave Mr. Aizawa a happy smile. "Well, I should get back to my class."

"Right. Thanks for informing me on the situation." Mr. Yoshida nodded.

"Sasaki, let's go," the Pro Hero said patting the boy on the back. Sasaki nodded, following the man obediently back down the hall.

"Alright you three, back to class," Mr. Aizawa drawled.

"So, you're not going to punish us?" Iida asked.

"For what? As Mr. Yoshida said, you did nothing wrong." Izuku felt a weight release his chest and exhaled in relief.

"Thank you Mr. Aizawa!"

"There's nothing to thank me for. Now get back to class," the man said sharply. The three students nodded and turned, practically sprinting to the room.

Izuku felt a little giddy as he plopped down into his seat. They hadn't gotten in trouble; they hadn't even gotten a lecture from Mr. Aizawa, despite the events at lunch. Maybe he was just tired from the USJ attack…

Mr. Yoshida seemed really nice, too. Maybe if he asked, Mr. Yoshida would tell him about the other students of Class Z. It would be interesting to learn about quirks that couldn't be controlled.

Izuku set aside the thoughts as Ectoplasm walked into the class. It wasn't the time to learn about dangerous quirks. That could wait. Now it was time to learn about math.

\\\

What is up?! Little Cat with a quick word about My Hero Academia Class Z.

This is the AU shared by Big Cat and myself. The series will be released in separate arcs or "volumes" and extra art and shorts will be released on my Instagram account so be sure to check for updates there as well. It might take a lot of time between volumes, since we only post completed arcs as a personal policy, but I, myself, will post updates on my aforementioned Instagram account.

I'm not sure what BC will do.

The rest of this prologue will be a series of short one shots about the other members of Class 1-Z.