Assassination! In Another World Chapter 1, an Assassination Classroom/暗殺教室 + My Hero Academia/僕のヒーローアカデミア Crossover fanfic

(A/N) Hey everyone! I know what you're thinking, and no, I'm not abandoning Threads Untangled. I actually have some big plans for that one, but it will take some time to write. This is just something to tide you guys over. I took Koda (Mountain Head) out of 1-A because he felt like he was the most useless for what I want to do.

Izuku: Sounds to me like you're putting it off.

Are we really doing this? You know, Mightless and a bunch of others have already done this.

Nagisa: Yeah, but did they have multiple characters show up, breaking the fourth wall?

YES!

Izuku: Chill out dude.

I already have people on my ass about Threads Untangled seemingly taking inspiration from it, before I told people what I drew from it. Now this?! I'm gonna go take a walk.

Izuku: I'll check on him, make sure he's OK.

Nagisa: Alright. Audience, sorry if I'm OOC in this. It's been awhile since Mr. Political has seen Assassination Classroom. Two years ago, I believe. Don't forget to favorite, follow, and review! Thanks!

Nagisa woke up, still groggy from what happened before. He found himself in what looked to be a hospital. The ceiling was an off-white color, and the walls looked to be an odd shade of blue. She could hear two people bickering outside her door.

"Thank you for bringing her to me, Midoriya. I understand that you're shy, but you should be here when she wakes up." He heard an effeminate voice say.

"C'mon, Recovery Girl, you know how I am with these things." A voice that sounded like a boy his age.

"I know that you're like this around girls," replied what seemed to be Recovery Girl, "but come on, really, Midori-" The door was suddenly kicked open, but Nagisa was being very careful not to let her assassin side show.

"First of all, I'm not a girl. Second, where am I. I know I'm not in Japan anymore." Nagisa stated, matter-of-factly.

"What are you talking about? You're in Musutafu, Japan!" the boy replied.

"No, Japan doesn't have these amazing powers like something out of a comic book. I may not have looked like it, but I was half-awake and saw some things while you were bringing me here. There was literally a guy shooting flames from his FISTS!"

"Oh, you mean Endeavor, the No 2 hero. Ya, soon after someone found you near where Stain had attacked, him and I got there. We all assumed you were attacked by Stain, but I'm guessing not, based on your reaction. I want you to tell me everything that happened up to this point."

Flashback

Nagisa was standing behind the building where he trained his abilities to become an expert assassin, his Assassination Classroom.

Suddenly, he felt a shiver down his spine, turning around.

"Who are you, and what do you want?" Nagisa said, pulling out a gun. "Come out, and I'll spare you."

"Simple, I want the end of all heroes, and I think you will do nicely." a mysterious, obviously filtered voice said behind him.

"I'm not like the rest. I don't work just for the money. It's a nice bonus, to be sure, but not my main reason." Nagisa replied. "And as for 'heroes', I have no clue what you're talking about."

"You will soon enough." the person said before shoving Nagisa through some sort of portal. He landed on his head and was out cold.

Flashback End

"So, you really aren't from here. Can you take me to where you found him?" Midoriya asked.

"Yeah, I had to have the coordinates memorized, both for my extracurriculars and my main school." Nagisa replied. "My name is Nagisa Shiota, by the way. Just call me Nagisa."

"Izuku Midoriya. Call me Izuku."

"YOU WERE ATTACKED AT UA?"

"What? No, I was attacked outside of classroom 3E! I don't even recognize this building! Can we just get inside?"

"Well, I can. Just wait out here, I'll get you a visitor pass."

"NO NEED, YOUNG MIDORIYA! I HAVE ONE RIGHT HERE!"

"All Might?"

"INDEED, YOUNG MIDORIYA! I WAS PASSING OVERHEAD WHEN I HEARD YOUR CONVERSATION! EXCUSE ME MISS, WHY DO YOU NEED TO GET INTO UA?"
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All Might could feel a very, VERY strong sting in his gentlemen's area. He saw that the blue-haired girl had shot him, but not with a normal bullet.

"Don't ever call me a girl. I was nice to Izuku because he rescued me, but I have no idea who you are, so why hold back? Good thing this thing doesn't carry any REAL bullets, at least for you."

"NAGISA, YOU SHOULD RUN!"

"Why should I? I've beaten GROUPS of people his size single-handedly. I'll be fine."

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"Can you survive a F5 hurricane?"

"Huh?"

"DETROIT SMASH! Eh?"
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"You really should be more careful about how you throw your punches, Mr. All Might. After all, you need to keep in mind what happens afterward." Nagisa said while holding what appeared to be a green knife to All Might's throat. "Believe it or not, I've seen you before, on a show called My Hero Academia. It's all the rage back home. I know exactly how you fight, as well as how to defeat you. An assassin can never be too careful, after all."

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"Wait, an assassin? I saved an assassin?"

"Yeah, you did, but I'm not professional. I just know a few tricks. Speaking of," Nagisa began, releasing All Might, "I want to speak to Nezu, see if he can figure anything out. And no, I don't have a 'quirk', as you call them."

In Nezu's Office

"So you're from another world, you say?" A man/bear/mouse thing said.

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"That's correct. Where I'm from, there's a small wooden shack that my school uses for the rejects, not this metropolis of a school."

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"And why did you attack the No 1 hero?"

"Jeez, this is starting to sound like an interrogation. He called me a girl, and let's just say that kinda set me off. Look, I won't go into detail, but let's just say my mom made me dress like a girl since she found out I was a guy, so I hate being called a girl."

"Listen, Mr. Shiota-"

"Nagisa is fine."

"Nagisa, you said you were an assassin?"

"Not professionally, but I do have some skills I picked up at school. If you ever find yourself in my corner of the potentially multiverse, don't tell anyone. It's kinda top secret where I'm from. Basically, Class 3E is a bunch of rejects that the entire school makes fun of and shuns because we're the bottom 5% in terms of scores on some stupid test. Suddenly, 70% of our moon exploded, and an octopus-type creature came to Earth, saying he would do the same to Earth if we couldn't kill him before we graduate. So, a guy from the government came to the school and taught us how to defeat a normal human in hand-to-hand combat, at least normal in my world. He also offered us a split of 30 billion yen if we succeeded. The octopus wanted to teach us though, and he was good at it. But, all of the teachers said that I was the best, so I think I was brought here for a reason."

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"And what might that be, Nagisa?"

"Before I fell through the portal, he told me that he want to end all heroes. I don't know the person, but I think he wants me to assassinate heroes. Also, sorry Mr. All Might. That was just a BB pellet I shot you with, coated with a special serum designed to kill Korosensei, the octopus man. This knife SHOULDN'T be able to hurt you. It's made of rubber, but is coated with the same serum."

"NO PROBLEM NAGISA! I AM THE ONE WHO SHOULD BE APOLOGIZING! I HAD NO IDEA WHAT WAS GOING ON WITH YOU! I'M SURE I'LL BE FINE WITH RECOVERY GIRL WORKING HERE!"

"Either way, we need to find this person. Nagisa, would you be OK with being a temporary member of Class 1-A while we work this out?"

"I'm fine with that, I just hope Izuku and the others aren't scared of me, especially if Izuku tells them what happened."

In Homeroom

"Who's the new girl?"

"I don't know, but she's pretty hot! Like an 8!"

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Nagisa felt a small boy grab her leg, trying to feel around his pants. In the blink of an eye, she was behind him with a knife to the smaller boy's throat.

"I wouldn't try that if I were you. I am a boy, after all." Nagisa said, letting his assassin instincts flow. Even the raven-headed kid was slightly freaked out. "Sorry, I hate perverts, especially ones that treat girls like objects." Nagisa said before kicking Mineta across the room.

"Settle down, class. What happened to Mineta?" Aizawa questioned, as the normally outspoken purple midget was in the fetal position in the corner.

"Sh-He happened." a kid with huge elbows said.

"And what exactly do you mean?"

"He clung to my leg, trying to feel around in my pants, thinking I was a girl. In response, I simply put a knife to his throat and kicked him across the room." Nagisa said.

"Moving past that, we are going to be holding 2v2 combat training. Here to teach it is:"

"I AM HERE! WALKING THROUGH THE DOOR LIKE A NORMAL PERSO- WHAT HAPPENED TO HIM?" All Might inquired, prompting Aizawa to tell him what happened. "AH, I SEE. MAYBE IT WILL TEACH HIM A LESSON. BUT, YOU SHOULD HAVE REPORTED IT, NOT TAKEN IT INTO YOUR OWN HANDS!"

"Where's the humiliation if it's private?" Nagisa retorted.

"FAIR ENOUGH! BACK TO THE MATTER AT HAND, YOU WILL BE SPLIT INTO 10 TEAMS OF TWO! THE TEAMS WILL BE DECIDED BY LOTS!

"THE TEAMS ARE DECIDED!"

Team A: Midoriya & Uraraka

Team B: Bakugo & Iida

Team C: Fumikage & Shiota

Team D: Todoroki & Ojiro

Team E: Aoyama & Mineta

Team F: Sato & Yaoyuzaru

Team G: Kaminari & Jirou

Team H: Shoji & Hagakure

Team I: Sero & Ashido

Team J: Kaminari & Sato

"AND THE TEAMS ARE C AS THE VILLAINS, AND TEAM E AS THE HEROES! VILLAINS HAVE 5 MINUTES TO SET UP!"

"So Tokoyami, what's your quirk?"

"Dark Shadow. I basically have a sentient bird made of shadows. Want to see?"

"Sure, why not? From what I've seen, it's weaker in daylight."

"Shadow?"

"Ya? Wait, you're the assassin that scared the hell out of everyone, aren't you?"

"Yeah, what's it to you?"

"Nothing, other than the fact that you managed to creep me out, the PERSONIFICATION of all things that bow to the darkness in the world. So how did YOU manage to creep ME out?"

"I'll explain everything when we get back. For now, let's focus on the heroes. One of the stipulations was that, if we, as the villains, are able to get a ink mark on the hero's neck, wrist, back of the knee, or achilles's, then they are out, since a real hit to that area would render them useless. Fortunately, I have the perfect tool for it." Nagisa said, handing Tokoyami a rubber knife with ink on the blade. "Also, do you feel any pain Dark Shadow does?"

"Some, but not much. Why?"

"In that case, hey DS? Can you touch the knife?"

"Of course I can, and don't call me D-AAAAHHH!" Dark Shadow screamed as it felt like its hand was burning at the touch of the knife. "The hell is this made of?!"

"Rubber, mostly. It does have a lining that will cut through my teacher, so there must be some relation between what you're made of and what he is made of. How fast can you move?"

"Mach 20, but I need to maintain some kind of physical connection to Tokoyami over here. Why do you ask?"

"Perfect! Do you mind if we spar during free time? I need to be able to beat a Mach 20 guy, for reasons I'll reveal later. Speaking of people we need to beat..."

"GRAPE RU-huh?" Mineta yelled, trying to stick both of the mock-villains, but mostly the assassin. He stopped when he felt something run along his neck.

"You really need to be more careful. You left yourself wide open, assuming that the assailant could dodge those grapes of yours." Nagisa said before pulling out her paintball pistol, shooting Aoyama in the chest. "Not to mention that you should always keep in mind what weapons they may have on them."

Everyone back in the observation room was amazed, with the exception of All Might, Eraserhead, and Midoriya.

"That was way too quick for him not to have some sort of speed quirk, but I can't see anything to prove it." Jirou said, "I just wonder what it is."

(A/N) Thanks for reading! Please, leave a review, tell me how I did. I may continue this if I get enough requests, but I have no intention of dropping Threads Untangled until it's done.