How's it going everyone!? OhataUchiha is here with a new crossover! And even better, I think this is the very first one of these on FFN! Yes, as you can tell, this is a Dragonball Z x Assassination Classroom! Now, I just finished the anime a few days ago, (dubbed as always) and I thought, 'Koro-sensei isn't all or Trunks can beat him.' Then it hit me. I can make that happen in the world of FFA (FanfictionNet). So now, here I am. So, I'm still debating whether to use Goten or Trunks, but I think Trunks makes more sense, given his connections would allow info on Koro-sensei, as well as the fact that Trunks is more likely to go to middle school. Anyway, I'm not going to make this a one shot, because that's boring. So, Trunks will let him live for soon to be revealed reasons. Anyway, let's get on with this!

Disclaimer: I do not own Dragonball, Dragonball Z, or Dragonball Super (GT isn't canon, not gonna bother with it). However, I do own Koro-sensei's uniform. Enjoy!

Chapter 1: Transfer Student

Trunks walked into his home, greeting his mother. "Mom, I'm home." He said as he dropped his backpack off his shoulders. He made his way into the kitchen to see his mother with a concerned expression, but not towards him. He looked towards the TV and saw the headline on the news. 'Destruction of the Moon.'

"Trunks, I'm glad you're home. We need to talk." Trunks complied and pulled out a chair, sitting down. "So, I was contacted by the government, and they asked me to produce special weapons, ones that can split atoms without damaging humans. I asked them what they were talking about, and they told me to turn on the news. After I was well informed, I was taken to a facility where there was this…yellow thing. I ran some tests on him and developed the first weapons, and they began to mass produce them."

"Um…alright…"

"This thing blew up the moon, and plans to do the same to Earth. I need you to stop him. I'd ask your father, but he'd make a scene out of it. It agreed to give Earth a chance by leaving the deed to a class of middle school failures. I've already made arrangements to get you in the class."

"Alright. I'll take this thing down no sweat!" Trunks said full of excitement.

"We have a transfer student today, class. His name is Trunks Brief." Trunks heard from outside the room. "Come in, young boy."

Trunks walked in and thought that this was all a big joke. "What the hell is that!? Don't tell me that this was the thing that blew up the moon!" he said, pointing to the clothed yellow octopus.

"Oh, it is all too true, Mr. Brief. Now, as you all may know, the Brief family is a very wealthy one."

"Hello, everyone. I was transferred here to aid you in the assassination of K-sensei. However, we don't have a need for ten billion Yen, so whoever is a part of this thing death will be split the reward money, with me out of the equation. I am very much informed about our situation and our mission. I hope we all get along." The students whispered among themselves, thinking about how it was their chance to have a free partner. "And, K-sensei?"

"What is it, Mr. Brief?"

"Know this. I will be the one to kill you and save the planet. My father and his rival, as well as his son, have had their chances to save the Earth. Now it's my turn." Trunks looked at him with determination.

Koro-sensei's face gained green stripes. "I would absolutely love to see you try, Mr. Brief. Now take your seat."

"Sure thing. In due time, though, everyone will be able to see just what I can do." Trunks gave a cocky smile and went to a seat in the back. Everyone took note of how he looked kind of strange with his purple hair and gray uniform. He took his seat in the back row and sat quietly. That guy…he sounds like Krillin…strange…

The rest of the period, Trunks looked out of the window, lost in a train of thought. He stared at the permanent crescent moon. Man…I have to kill this thing? No problem…but I was hoping for more of a challenge. Someone or something way stronger than Abo and Cado. But not as strong as Beerus…Gotenks learned that the hard way. His thought process was lost as a strong gust of wind blew across the room. Gohan saw Koro-sensei grab a notebook out of a student's hands.

"Suguya! Not a bad likeness, but I'm a little hurt by the jaw line." He said as he showed the drawing to the class.

"You don't have a jaw!" the student shouted.

The bell sounded and Trunks was ready to fall asleep. He didn't know why he needed to be in class to kill this guy, but he was told about E Class. He wanted to give this teacher a chance to give these students a future before he killed him.

"That's lunch people." He said. "If you'll excuse me, I have some important off-campus business to attend to."

"Tofu from China?" a student asked.

"Actually, I'm catching a ball game in the big apple." He corrected as he opened the window. He sped away and kicked up dust around the room. Trunks smiled. So…he can fly, huh? And he's pretty fast. Maybe this won't be so boring after all. Trunks sat up and walked over to the blue haired guy.

"Hey, are you Nagisa?"

"Yeah…you're the new guy."

"My name is Trunks. It's not hard to remember. It's nice to meet you. I hope we'll get along well."

"If you don't mind my asking, Trunks…why are you here? I mean, you come from one of the richest families in the world, and you're family is full of geniuses."

"I was transferred to this class to kill K-sensei."

"Well, good luck. You have just as much a chance as the rest of us. But we're only humans, and junior high students at that. There's no way we can do this…"

"There's no chance you can do this, but I'm a different story."

"What do you mean?"

"You'll see in due time, Nagisa." Trunks said as he went back to his seat. Nagisa made his way to the door as Mr. Karasuma walked in.

"Children, any progress on killing the tentacle menace?"

"Don't worry, Mr. K. I'll kill this thing no problem." Trunks said.

"Easier said than done." Nagisa responded.

"In all seriousness, this is E-Class, yo. You gotta lower your expectations." One student in the back answered.

"With all due respect, sir, he's just too quick."

"Like so quick you can't even see him sometimes."

"Like you said yourself, he tops out at Mach 20. How do we kill something like that?"

"I don't know…"

"I saw." Trunks spoke up once again. "I saw him clearly when he took that dawi-" he was cut off by a student who was always seen with two other rebels.

"Shut the hell up with that, will ya!? You may think you're Mr. Powerful, but you're not! Whether you're family is rich or not, you're an E-Class failure like the rest of us!"

He let out a sigh. "Fine…I guess you won't believe me until the time comes. When he comes back, I'll show you what I can do." He gave him a bigger-than-normal overconfident face.

Trunks had spent the lunch period with Nagisa, talking about how he ended up there. Eventually, Kayano joined in, gaining him a new friend. "Yeah, you're going to see what I'm made of, but honestly, it's nothing compared to my dad. He's one of the most powerful people on the planet."

"No way! Your dad is Hercule?!" Nagisa asked.

"No, even stronger. Although, my best friend's big brother is married to his daughter."

"No way! Nobody is stronger than Mr. Satan! I'm surprised they didn't get him on the job."

"He must have wussed out when he heard about the moon being blown up. My mom would have told my dad about it…but he was off training again." Nagito suddenly stood up.

"Sorry, but I have to get these papers turned in." he said as he left the room. Trunks looked out the window and saw Koro-sensei. His eyes instantly lit up.

"FINALLY!" he broke through the window, surprising everyone. He stopped moving his tentacles, holding a student in midair. "K…no…Koro-sensei!"

"Why, what is it, Trunks?"

"Let me take a shot at you with a knife!" he shouted. Everyone looked out of the window.

"We'll continue this later, Okuda." He said as he put him down. His face gained multiple green stripes. "Go ahead, but I'll have you know that I can move at Mach 20. It won't be easy to hit me, especially with a knife."

"Don't worry." He pulled off his uniform, revealing the green fighting gi and orange belt he wore underneath. He turned to the class. "Hey, can one of you guys bring me a knife?" everyone could clearly see his built, muscular upper body. Multiple girls blushed at the sight of this.

"And later we're going to have to talk about that window!" Koro-sensei scolded.

"Don't worry about it, K-sensei. My mom will pay for that." He said as the student who yelled at him earlier handed him a knife. "Thanks." He turned to his opponent and the student left. Everyone watched intently, but the very next thing they could see was Koro-sensei's surprised face as both of his arms were severed, sprinkling like a sliced hose. "So, what was that about Mach 20?" he said with a smile.

"B-But how!? I couldn't even see him!" Koro-sensei said nervously.

"No need to be scared. I'm going to slowly cut you down from time to time, but I won't kill you yet."

"No way!"
"Impossible!"
"He's faster than Koro-sensei!"
"What is he?!"

Trunks held the knife by the blade and threw it down, impaling the ground with it. "Don't doubt me. I prefer to have fun, so instead of doing my work, I greatly procrastinate. Guess I belong in E-Class, after all." He said as he left towards the building. He was greeted by Mr. Karasuma, who simply said.

"We need to talk."

"Alright, what exactly are you?" he said. The two of them walked into the teacher's lounge and sat down. "Are you another genetically enhanced life-form?"

"No, sir. According to my father, I'm half-Saiyan."

"Saiyan?"

"Yeah. In his words, a race of proud warriors that specialize in combat whose planet was destroyed."

"Wait, so you're telling me that you're half alien?"

"Pretty much. I mean, is it really hard to believe, though?"

"I guess not. So you claim to surpass the octopus' speed, and best him in combat. Is that supposed to imply that you, too, can destroy the Earth?"

"Yeah, I guess. But me, my dad, my best friend, his brother, his dad, and his dad's friends have all been training hard for a long time to keep the Earth safe. You don't have to be an alien to fly, ya know. You just need the right training."

"I see. Well, there's not much I can do. As far as we know, you're even bigger threat, but we can't do anything about it for now. But why won't you kill him yet?"

"Because that's no fun. And besides, I read up on E-Class, and I thought if anyone can teach these students, it's the genetically engineered super-being. Are we done here?"

"Yes…you can leave. But remember this, you are our last hope, Trunks Brief. I'll allow you to put this off for now, but eventually you will have to take care of him."

"I understand."

That's it for chapter 1, everyone! This is placed in episode 2, btw. Now, I would just have Trunks kill Koro-sensei, but I like to drag things out. And besides, when you're as big a Dragonball Z fan as I am, you imagine what a Z Warrior would do in EVERY situation possible. So yeah. I hope you all enjoyed, and chapter 2 coming soon. Until next time guys, STAY CLASSY!