Koro-sensei had the appearance of a yellow bipedal octopus. He was about three meters tall, and possessed a large, bulbous head with a large smile and small, beady eyes. He used two feelers as arms, with two fingers each, and utilized the rest of his tentacles to walk with. He wore a black academic dress, a small black square academic cap with a yellow tassel, and a large black tie with a yellow crescent-shaped moon on it. According to Korosensei himself, his nostrils are so small yet when discovered, it seemed that he had four eyes. The color of Koro-sensei's face changes depending on his mood.

Kimura is one of the relatively proactive students when it comes to assassination and aims to claim the 10 billion yen reward. It is stated that both of his parents are police officers, and they have a high sense of justice, thus earning him "Justice" as a name.

The students of class 3-5 stare up at the humongous monster standing in front of the class in horror. What the hell is this thing doing here in their classroom, where is Shiota-sensei?

The octopus-like monster let out a weird laugh. "Nyurufufufu~ Nice to meet you, I was the one who blew up the moon several years ago... Seeing as I've become your homeroom teacher, I look forward to working with you."

Wait... HOMEROOM TEACHER? What? How did Shiota-sensei not inform them about this?

A man standing beside the octopus took a step up. "My name is Kimura Masayoshi. I would like you to understand that what I am about to say is classified government information... Now cutting straight to the point, I want you all to kill this monster."

A girl raised her hand.

"Yes..?" The man glanced at her.

"Kiryuu Natsuka. Why are we not informed about this earlier? What about Shiota-sensei? Is he not teaching us anymore?" The girl asked.

Kimura took a deep breath before replying. "As I had earlier, we wanted to keep this information as discrete as possible so it was not informed to you all beforehand. Shiota Nagisa has been dismissed of his post and he has been banned from communicating with you all. I would suggest that you all forget about him, as he plays no role in the future."

"But how are we going to kill this monster?" Another student asked. "We are only highschool students."

"Nyurufufufu~" The octopus laughed. "I do not want to be killed by just anyone but... if I become the homeroom teacher of Paradise High, Class 3-5, then you are welcomed to try."

"We don't know his goal." Kimura glared at the octopus in front of him. "But the government consented, on the condition that he cause absolutely no harm to you students. Our reasons are twofold. As he will come to this classroom everyday as a teacher, we can observe him, and you will have the chance to kill him at point blank range."

The students stared at the man before them doubtfully. They remembered their lessons with the chibi of a homeroom teacher and the times they had when they tried to 'kill' him. They have never successfully landed a hit on him.

"If that is not enough motivation for all of you..." Kimura cleared his throat. "The reward for successful completion is 10 billion yen."

WHAT?

"It is an appropriate sum. After all , the assassination's success means the Earth's salvation."

Another student raised his hand. "How is it Earth's salvation?"

"Well... nuru," the octopus-like monster laughed. "I will be blowing up Earth next!"

"I would like you to strike if the opportunity presents itself. However, this must be kept a secret from your family and friends." Kimura continued. "If the Earth disappears, there will nowhere to run."

The monster let out another weird laugh. "Now everyone, let's spend this final year in a meaningful fashion!"

What. The. Hell.

Class 3-5 of Paradise High, the class full on delinquents, now a class for which an octopus is teaching.

The students are already missing their previous teal headed teacher.

Natsuka whipped out her phone. She did not care about Kimura's warning about communicating with their ex-teacher. She wanted to find out more about this bizarre situation her class is in. She quickly dialed the number and placed her phone by her ear.

Beep. Beep. Beep.

The phone continues to ring, but Shiota-sensei did not pick up.

She sighed.

Nagisa dodged a swipe at him and landed a stab at his attacker. He could feel the buzzing of his phone along his thigh, but he was too occupied with dealing with this yakuza the government had ordered him to eliminate.

He hoped his class is dealing well with the substitute teacher he gave them. Due to some circumstances *coughs*Karasuma*coughs*, he was unable to contact his students about his absence from his teaching duties that day. He had only time to contact one of his friends to substitute his class for him.

Sometimes he wonders why he took up this part time job as the ministry's assassin. It is not as if he is not paid well by the school anyways.

"Nyurufufufu... That's not enough to kill me... Jin-san." The octopus laughed as he dodged a swipe aimed at him with ease, his yellow face had green stripes on it. "Now let's continue with the lesson..."

With one of its slimy tentacles, the octopus picked up a chalk and wrote on the blackboard. "Let's try writing Tanka poems based on a theme. Please end it with "tentacles" in the last seven syllables. Once you have written one, bring it up to me so I can check for proper grammar and to see if you were able to express tentacles in a beautiful way."

"Sensei?" A blonde girl sitting at the back of the class raised her hand. "What's your name?"

The octopus paused in his actions and thought for a while. "You can call me... Koro-sensei."

"Koro-sensei?" Another student echoed the name.

"Yep, because I'm unkillable~! Nyurufufufu~!"

The students banged their heads on their desks.

Where is Shiota-sensei when you need him?

Kimura stared at the octopus standing before him. "You're really enjoying, aren't you?"

"Of course I am! This is a once in a lifetime opportunity!"

"School ends in one hour."

"It's time to pull of the last trick~!"

"The monster has gone maaaad!"

"It's gonna kill ussssss!"

"HEEEEEELP!"

Koro-sensei was moving around the classroom at the speed of light, sexually harassing the students with his tentacles, knocking over random stuff.

Kimura just stared at the scene before him. "Did I not mention that he can move at a speed of Mach 20?"

"YOU DID NOT!" The students yelled, angry that their classroom is in a mess. It took a long time for them to clean it up the last time.

"It's so fun in here. Come on students, let's sing a song together!"

Everyone sweatdropped.

"Mina-san ohayou gozaimasu, koro taisou no jikan desu yo hari kitte ikimasho! (Lyrics to Koro-sensei's character song, Koro Taisou)"

Sweatdrops even more.

"And... Happy April's Fools Dayyyyy!"

Wait, what?

"Happy April's Foooools!"

The octopus like figure yanked off it a head, revealing a blonde girl's head. "Man, that was fun!" She exclaimed. "Itona really outdone himself this time. This suit is so realistic! The voice synthesizer even changed my voice!"

Nagisa aimed and threw a dagger at his perpetrator, successfully killing him with the attack.

"Finally," He mumbled to himself. "That was taking way too long."

He drew out his phone from his pocket and checked his phone log.

Miscall- Kiryuu Natsuka

Frowning, he dialed his student's number, surprised when Natsuka picked up the call the second he had dialed the number.

"Natsuka-chan, is something wrong? Why did you call me?" He asked.

"Heya, Nagisa. Long time no see," a voice that did not belong to his student came from the other line. Nonetheless, he recognized the voice easily enough.

"Nakamura-san, what are you doing with my student's phone?" He asked, bewildered. "Did I not ask Kimura to substitute my class for me? Why are you there?"

A laugh could be heard at the end of the line. "Happy April's Fools!"

With that, the call ended, leaving Nagisa to stare at his phone, shocked with no words to say.

Nakamura: Wooooo

Karma: Someone's happy

Okajima: Wonder whats the occasion

Nakamura: Happy April's Fools!

Kayano: Ah

Kayano: That

Fuwa: Happy April's Fools guysss!

Karma: I pranked a lot of people today

Karma: I realized that even though we are Japanese

Karma: Most of the population cannot stand wasabi

Okajima:...

Okuda: Takebayashi tried to play a prank on me

Okuda: But the boss stopped him before he could do so

Hazama: No one understood my April Fools prank

Kayano: What did you do?

Hazama: I dressed up as a vampire and knocked on random houses' doors

Okajima: ...

"Hey Itona, you were working on the Koro-sensei suit?"

"Yes, why?"

"Is it finished?"

"It should be."

"Can I borrow it?"

"... What are you going to do with it?"

"I'm going to prank Nagisa's class."

This is why there was no Author's notes at the beginning. Honestly, I do not know why I even wrote this. It was a last minute idea for April's Fools, but um... yea?

I still don't know why I wrote it. It's not even funny.

Argh.

Still gonna post it.

Yours,

BlueSkyBlue,

a.k.a. Otonashi Hayuka