No One POV

Class 3-E is nervously awaiting the arrival of their homeroom teacher.

Some of them were nervously glancing at their classmates. Some would give them a reassuring look, while others wouldn't much help as they'll give them a look that they're on edge too.

One student is even biting her lip hard as one classmate gives a small tap on their arm. She almost jolted up and looked at her classmate, who gave her a soft smile. It helped her nerves as she quickly took a deep breath.

Suddenly, the building shakes as the girl quickly at the window servicing the area. The classmate still gave a reassuring smile, their eyes had a look of seriousness.

The door opens, and the homeroom teacher is now present. Once there, he sets the roll book on his desk and calls for homeroom to begin, "All right people. Let's get started, shall we? Class Monitor, if you would do the honors."

The teacher has the appearance of a yellow octopus. He is about three meters tall and possesses a large, bulbous head with a large smile that rarely breaks or moves and small, beady eyes. He uses two tentacles as arms, each having two feelers as fingers, and utilizes the rest of seemingly jelly-like limbs - his tentacles - to walk. The teacher has a pair of hidden nostrils, which make him appear to have four eyes if detected.

The teacher wears a black academic dress, a small black squarish mortarboard cap with a yellow tassel, and a large black tie with a yellow crescent-shaped moon on it.

The class monitor stood up. A petite-framed boy with blue hair and azure eyes. He keeps it in two pigtails.

"Right! Ready!" The Class Monitor calls it and everyone stands ready with their firearms and begins to fire when he yells "Bow!". 

The teacher dodges the bullets and begins taking roll. "Isogai?"

"Here," Isogai spoke. Isogai has somewhat spiked dark brown hair with two small hair antennae at the top and pale gold. Isogai has been described as being very attractive and is one of the most popular members of Class 3-E.

"What's that?" The teacher asks as they are still dodging the rounds of bullets, "I'm afraid I couldn't make it out over all the gunfire."

"Here!" Isogai yells.

"Excellent!" The teacher cheers before rolling to the next student, "Okajima?"

"Here!" Okajima answers while firing his rifle. Okajima has short, black hair in a butch cut and thicker brows compared to other students.

"Okuda?" The teacher calls the next student.

"Here." Okuda reloads her firearm. Okuda has black hair (sometimes with a purplish tint) styled into twin braids that reach just below her shoulder and dark purple eyes. She wears glasses and has a more petite frame than most of the girls in Class 3-E.

"Kataoka?" The teacher calls out his next student.

"Here." Kataoka is a tall girl with long light brown hair that is kept in a ponytail with straight bangs. She is described as being "dashing" by some and according to fashion reviews of the students, she also has the physique and making of a model. This combined with her personality and talents earned her the title "Ikemegu".

Bullets were rolling on the ground as the students were still attempting to kill their teacher.

"Kayano?" The teacher begins calling out his next student.

"H-Here!" Kayano is a short girl with light green hair that is always fashioned in unique cat ear-styled pigtails, hazel eyes, and a running gag for her appearance that she does not have noticeable breasts like the other female students in the class, giving her the nickname "Forever Flat".

"Kanzaki?" The teacher calls to his next student.

"Here." Kanzaki is a pale-skinned girl with straight mid-back length black hair styled in a hime-cut that has bangs hanging over her eyebrows and light-brown eyes. She is noted for being very beautiful by everyone in Class E, which is one of the reasons why she is the most popular girl in the class.

After the roll call is finished and the students are worn out, the teacher expresses his happiness as there are no absences. "Excellent. All are present and accounted for. No tardies! Congratulations!"

"He's fast," One classmate complains as Isogai looks at his firearm. "The whole class opened fire and he doesn't even have a scratch."

'Yep.' The class monitor, Nagisa, looks at his pistol in disappointment. 

'We're assassins and our target...Is our teacher.'

"No luck today either, eh?" The teacher shrugs, "That's too bad. What's the lesson here? Numbers are no substitute for inventiveness, perhaps? That any hack can point a gun and pull the trigger? Some of Column A, some of Column B? I get that you were trying to at least cast the net as widely as possible, so to speak, but the approach lacked originality. When the target clocks at Mach Twenty, an assassin has to think outside the box."

"Ha. Right. Mach Twenty." Maehara scoffs, "No freaking way did you dodge that hail of bullets!"

Hiroto is fairly tall for a middle school student. He has wavy mid-short, and both eyes and hair are orange-brown. He has been noted to be very good-looking from the girl's point of view. He is one of the few that is popular in the whole school despite being in the E Class.

"He's got a point." Sugino agrees as he looks at their bullets, "I mean, these are only BBs, right? For all we know, you just stood there and took 'em like a champ."

Sugino has the generic short, spiked black hair for male shōnen characters and has dark blue eyes. He sports red wristbands.

The students begin chiming in their complaints the teacher sighs. "Collect the ammunition and bring it here."

A student hands over their firearm, when suddenly the teacher's right tentacle is shot off. The students gasped and screamed as the teacher quickly looked around to who was responsible.

"They're known as "anti-me BBs"." A student spoke as their voice was calm considering what they did, "Harmless to us, but able to split your cells like a knife through warm tofu."

The student is a fairly muscular man of short stature and possesses a feminine appearance as his beautiful red eyes don't help. He has long black hair that fades to blond, styled at the end tied in a ponytail, with a white, yellow, and black butterfly ornament.

"This was developed by the government for that express purpose." The student explained as he gave a fake sadness, "But, after a few seconds, you can regenerate a new one."

Just after the student explained the bullets, the teacher regenerated a new tentacle. "Of course, while it's not lethal to us, they can still hurt us. So, let's not use them at each other, and use them solely at our teacher before graduation."

The student had their smile back as they had their hands clapped.

"Yes! Excellent explanation Y/n!" The teacher wiggles their tentacles in joy, "Safety is a top priority! Now then, please put those firearms away, and we can begin class!"

'Kunugigaoka Junior High, class Three-E. The Assassination Classroom.'
'The bell rings, another day begins.'

The class has begun, and the teacher is in the middle of the English lesson. 

"Okay, here's a puzzler of you." The teacher turns to Isogai, "Isogai! Which of these four tentacles is the odd man out?"

He shows four tentacles each being shown in a different color. Blue, White, Pink, and Green.

"Umm, the blue one?" Isogai guessed. Ding Ding Ding! "Excellent!" The teacher congratulates, "The boy who is standing" employs "who" as a relative pronoun. A relative pronoun..."

While continuing, Kayano whispers over to Nagisa and Y/n, "Hey, Nagisa, Y/n. Check it out."

The two boys turn as she shows them the crescent moon outside the window. "Cresent moon's up. During the day. Neat, huh?"

This prompts Y/n to wonder and think back as to how he and the rest of Class E ended up in this situation, noting that two things happened at the beginning of their third year:

The first thing was the moon exploding into a crescent, which caused a breaking news report all over Japan. 

"Ahh...We interrupt our currently scheduled program for this breaking news bulletin..."

"This just in. A portion of the moon has been vaporized. Some sources estimate over 70%. I repeat: according..."

"What does it mean? Astronomers the world over are struggling to figure out just that."

The second thing was the creature who destroyed 70 percent of the moon appearing in Class 3-E, declaring that he'll do the same to Earth in a year, stating that he's now their homeroom teacher, and prompting the entire class to feel that there were so many things wrong in this situation. 

"Hello! How are you?" The Octopus Teacher greets the students, "So, I'm the one that blew up the moon."

"Huh?!" The Students said at one.

"Next year, I attend to do the same to Planet Earth." The Octopus Teacher announced, "But never mind that now, I'm gonna be your new teacher! Isn't that exciting?!"

'There are so many things wrong with this picture.' The students instantly thought together.

A man then introduces himself, "Uh, I'm Karasuma. I'm from the Ministry of Defense."

Karasuma is a handsome young man with spiky black hair and eyebrows and piercing dark eyes. He has a tall and muscular build. He dresses professionally in a black business suit with a white shirt and a black tie. He is described as being "cool" by the students.

"What, uh, what I am about to tell you we in the business call "classified." He sighs before he's blunt and tells the students, "I'm gonna need you to kill this thing for the sake of mankind."

The students start gasping, "Excuse me?!"

 "Sir, if I may?" Y/n raises his hand as Karasuma nods, "You want us, mere children, who all carry no credentials in such profession, to assassinate an alien, who destroyed nearly 70% of the moon-?"

"A-bah-bah-bah-bah-bah!" The creature interrupts as he is offended, "I am an Earthling born and bred, thank you very much!"

"Oh my!" Y/n gasps, "I'm so sorry! I just never saw a person who looked like the mixture of a mac-n-cheese octopus! Please forgive me!"

"M-M-Mac-n-cheese octopus?!" The creature shouts in repeating.

Karasuma coughs to interrupt, "I'm not at liberty to discuss the details at this juncture. I'll just say, he's telling the truth. His threat is all too real. As of this coming March, he will obliterate the Earth."

"Apart from you, the only people who know this are world leaders. If words of this leak out to the public, we'll have widespread panic on our hands. He must be terminated soon and with extreme prejudice. Which means that you must become assassins."

He quickly pulls out an Anti-Sensei Knife and begins attacking while explaining the creature's abilities.

But, the creature is incredibly fast and dodges the barrage of attacks.

"Now, you'll notice he's incredibly fast!" Karasuma explains

While dodging, the octopus teacher begins to meticulously trim Karasuma's eyebrows. "And for some reason he likes grooming eyebrows. Immaculately!"

"You're looking at a being so powerful he can turn the moon into a crescent and has a max speed of Mach Twenty. If he gets away, Earth will be left helpless, awaiting its destruction."

"He makes it all sound so grim, doesn't he?" The creature closes his eyebrow-trimming kit, "Cheer up! I've graciously made your government an offer. "Stop making fools of yourselves trying to kill me," I said. And let me teach Kunugigaoka's Class 3-E."

'...What?' Nagisa thought as he listened.

"We didn't have much of a choice," Karasuma states that they don't know his reasons. Still, they were forced to agree on the condition that he doesn't harm any of the students and that there were two reasons. 

First, if the creature comes to the classroom every day, the government can monitor and know his location most days. 

The second was that it gave thirty people the means and incentive to kill him from an extremely close range.

The flashback ends as a student tries to shoot the teacher. The teacher uses the chalk to catch the bullet, now scolding them, "Nakamura! I distinctly remember saying no guns discharging in the classroom!"

"I know..." Nakamura put her head down. She is described as the "cool and gorgeous girl" of Class 3-E with long straight strawberry blonde hair that is parted in the middle and worn swept behind her shoulders, and aqua blue eyes with notably long eyelashes. The colors of her hair and eyes give her the appearance of a stereotypical Caucasian girl, even though she is Japanese.

"Back row, young lady." The teacher points at the back of the class, "Think about what you've done."

Nakamura groans as she goes to the back of the classroom. To her, she was glad that she could be near her classmate Y/n, "Y/n, can I take a glance at your notes?"

"Sure." Y/n hands over his notes but when Nakamura tries to see the notes, he quickly covers them, "After you thought about what you've done."

"Y/n!" Nakamura whines as Y/n boops her nose and continues taking notes.

Y/n went back to his notes, but there were more than just lessons. Lately, he's been observing the small details about his teacher. Noticing the timing of his regeneration, the reaction to each given scenario, and many other observations.

At first, he was scolding himself for not trying hard to get answers, but what the reward was when assassinating his teacher, immediately shifted his mind.

"Do the deed and you get ten billion."

'I mean, it does make sense since we're saving the Earth.' Y/n looks at his teacher, 'And by the fact on it's out mac-n-cheese octopus teacher we have to kill.'

The teacher sneezes, "Who has been talking about me? Confess!"

Y/n raises his hand, "I'm sorry sensei!"

The teacher put his tentacles at his hip, "Now Y/n, would you mind telling the class what you were thinking about?"

Y/n stood up and he looked around his classmates, who were all cautious as they didn't want Y/n to be in trouble. Y/n takes a deep breath, before smiling, "I was thinking about having mac-n-cheese octopus for dinner!"

"Y/n! How many times must I repeat?! I am a human born and bred! And as your teacher-!" The lunch bell sounds, interrupting the teacher. "Saved by the bell! I'm going to have some Maop tofu from China!"

He leaves at Mach 20 as Y/n laughs and looks at his classmates, "Okay! It'll take him about ten minutes to get to China's Sichuan province, the home of Mapo tofu."

"So just to be clear," Maehara chimes in. "We've ruled out missiles?"

Y/n giggles, "Given how he can break the sound barrier while grading our paper, I find it difficult even if we could access such an arsenal."

"Yeah." Isogai agreed with Y/n as he showed his completed homework, "It even came with a doodle with it."

"All things considered," Nakamura joins the conversation. "He's not even doing a bad job."

"I know, right?!" Hinano shows her notes, "He tutored me on algebra and I killed it on our pop quiz the next day!"

"Yeah. But at what cause though," Mimura looks down. "We get our grades up just in time for the world to end."

"Well, college wasn't happening either way." Okajima leans in his chair while looking at the ceiling.

"Come on," Y/n pats Okajima's head. "The saying; "Live fast die young" is right now happening, so no point in looking at the negatives."

"Yo, Nagisa, Y/n." The two boys turn to see their classmates Terasaka, Muramatsu, and Yoshida. "Look alive, you two. Time to put our money where our mouth is and get this done."

Terasaka has short, spiky, brown hair which is dyed blonde around the sides. He has a bulky body which he uses to intimidate people with light green eyes.

Takuya has dirty blonde hair and his eyes are small and black, to the point of appearing like he has pupils, but no iris.

Yoshida is a boy with dark brown hair that cascades into dreadlocks, along with a pair of sharp dark eyes with small pupils.

Nagisa nods as Y/n smiles, "Mkay~!" The five of them went outside as some students watched them sighing.

"Man, I don't know how Y/n can stand those guys?" Maehara asks as he crosses his arm. "Yeah," Sugino nods, "But it seems like he's the only one they'll ever even listen to. They'll mainly look at us as if they want to fight us."

"You know, in some way, that's what makes him special." Isogai looks at his notes, "He knows how to let people like them feel safe around him and how to sway people's hearts."

Nakamura covers her mouth from laughing, "No shade, but that sounds like someone gushing over their crush."

Isogai froze as three males slowly turned to him, "It. Does. Yuma Isogai."

Outside, the five boys were talking over their observations of the teacher.

"So we know the octopus's face changes color depending on what mood he is in." Terasaka asks Y/n and Nagisa, "Have you two been keeping track like I asked? Gimme the specs."

Nagisa was about to go over his notes but Y/n stopped him, "Nah."

Terasaka froze, "What was that?" Y/n walks over to Terasaka as they are now face to face, "What do we say when we ask for something?"

"This some joke?" Terasaka threatens as he stands up but some shadows are being shown with Y/n's smile.

Teresaka clicks his tongue, "Please, give me the damn notes."

Y/n claps his hands, "Very good! I'm glad that you evolving considering I have to ignore you because of how embarrassing to know that preschoolers have better mannerisms than you!"

Teresaka's face changes to extreme anger as Y/n gleams while nodding at Nagisa to go over their observation notes.

"E-Eh..." Nagisa stands confused before going over the notes, "Right, I guess for starters, green stripes mean he feels cocky. If we give a wrong answer, his face changes to a dark purple. But if we get the answer right, his face would turn bright red. What's interesting is every day after lunch, without fail..."

"Blah, blah, whatever!" Teresaka interrupted, "We've got more 'n enough. When his guard's down, that's when we make our move. Well, at least you do."

Nagisa looked a little nervous, "Yeah. About that, I..."

"Don't start! We've been over this!" Teresaka yells. Y/n raised an eyebrow, "Been over what?"

Nagisa froze; "I think we forgot to tell-"

"No." Y/n immediately spoke as Nagisa looked confused, "Whatever the plan is you two correspond to kill him. No."

"Really?! Even the world is done for?!" Teresaka turned his anger towards Y/n, "Wake up! We're Three-E! Everyone expects us to be thugs and murderers anyway! You know what the E stands for, right? End of the line. Think they shuttle us up the mountain every day for the view? Sorry to burst your bubble, but society doesn't want us."

Tersaka traps Y/n with his arms at the wall, "When do nobodies like us have a shot at the kind of cash at stake here?! This is our one-way ticket out of the boonies! No guts, no glory."

Terasaka takes out a small drawstring bag and gives it to Nagisa and tells him to not screw up. Nagisa then thinks back to when he was dropped to Class E. He recalls the ridicule and rejection from his classmates.

"You hear about Nagisa? They're chucking him to E-Class."

"Heh. Shocking. What else are they going to do?"

"That's one less name on my contacts."

"Yeah. How messed up is it that we even know someone like him?"

While thinking back, Y/n patted his shoulders. "Hey, we can think of a different-"

"No." Nagisa cuts in, "I'm gonna do it."

Both kids' ears twitch as they hear their teacher's flying who lands in front of them, holding a missile. "Hello there! I'm back!"

"Oh, okay. Umm, sir..." Nagisa was trying to ask a question but didn't know how to approach it till Y/n chimed in, "What's with the missile?"

Their teacher replies, "A souvenir from the Japanese Self-Defense Force that tried to ambush me in the Seas of Japan."

Nagisa and Y/n looked at each other, thinking the same thought, "Must be lonely spending your life in the crosshairs." To which their teacher disagrees, "Quiet the opposite! Reminds me of how amazing I am!"

Y/n caught Nagisa's head rising when he heard their teacher boosting. "Now then, inside for fifth period please."

Nagisa and Y/n nodded as they saw their teacher heading inside. They both looked at the bag as Nagisa looked at Y/n, "Do you trust me?"

Y/n raised an eyebrow, "Nagisa...?" Then Nagisa gets closer to his classmate, "Do. You. Trust me?"

There was a brief moment of silence as the two of them were staring at each other, neither one of them was batting an eye away from each other, or blinking. Y/n's red eyes were battling against Nagisa's cold blue eyes till they sighed and smiled, "Okay, go for it."

The fifth period has begun, and the teacher tells his students their assignment, "Okie-dokie! Your assignment this afternoon is to compose a short poem. The final line should read "Was tentacles all along". When you complete the assignment, kindly bring them forward. You will be graded on creativity, grammar, and overall beauty of expression."

"Here's an example: "Not the storm of garden's snow of flowers moving on, but sprouting there instead was tenacles all along."

"Yeah because that makes a whole lot of sense," Kurahashi commented before they all started their assignment.

To the students' acknowledgment, their teacher takes their "break" and his face turns light pink, signaling that he's tired. Nagisa gets up with his poem in hand and steadily walks over to him, but only Y/n, knows that Nagisa is hiding a knife and the folded paper. 

'Every day after lunch without fail, he gets sleepy.' Nagisa noted in his mind, 'I can tell he checks out when his face turns pink. All signs to this being the right moment.'

Once he reaches the teacher, he pulls out his knife and strikes only to be stopped. "What did I say about thinking outside the box?" The creature then tells them. 

At that moment, Nagisa reveals the grenade and latches on to the creature thinking that they have to prove themselves by any means necessary. Terasaka pushes the button that makes the grenade go off, and BBs fly everywhere. 

Y/n gasped as students were screaming as they all ducked down. Terasaka, Muramatsu, and Yoshida begin cheering and the other students go off at him asking what did he do.

To then Y/n looked at the three boys with everyone noticing that he wasn't smiling but was having small signs of anger. "What did you give him?!"

"What? You have a better idea?" Terasaka tells them what gave Nagisa. "I gave him a modified toy grenade but filled it up with gunpowder and three hundred anti-sensei bullets at high speed."

"Did you forget that it can still hurt us?!" Kayano argues Terasaka's idea, "With him being a suicide bomber, and with that many bullets at high speed-!"

"Don't worry, I'll pitch in on his medical bills," Terasaka promises but he discovers a thick membrane covering Nagisa. "What the hell?"

Kanzaki takes a look, "The membrane, protected Nagisa."

The teacher's voice is heard, "It's a husk, I shed my skin once a month. I wrapped it around your classmate to protect him from the blast."

Nagisa breaks out of the husk as Y/n rushes in to check on his classmate's condition, "Nagisa! Are you okay? How many numbers am I holding?"

Nagisa blinks as he takes a look, "Umm...three, five, two, two, four, none." Y/n sighs before the entire class feels the air turning ominous.

"Terasaka. Muramatsu. Yoshida." The class looks up at the ceiling as they see their teacher but with a different expression.

'Okay, that's a new face.' Nagisa starts shaking as he holds on to Y/n.

His face begins to turn pitch black, signaling that he's furious. "This was your doing. Wasn't it?!"

He then speeds out of the room and throughout the town at Mach 20. The class was silent as they all didn't know what to expect till he came back with Terasaka, Yoshida, Muramatsu, and the rest of the students' house nameplates. 

"Here's the deal kiddos," He threatens them by saying an agreement he made with the government. "The agreement I had with your government forbids me from harming you. But there's a catch. If you pull another irresponsible stunt like that again...There's nothing said I can't harm someone else. Family...Friends...Everyone in the world expects you if I feel like it."

The class felt dead as some of them were shaking, and some of them were hugging themselves to stay calm, they had to stay calm. Y/n was looking around until he found his nameplate but instead found a nameplate that belonged to someone he knows his eyes widened at how much their teacher knew them.

"Go on! Threaten us!" Terasaka goes off and tells his teacher that he is not afraid of him. "Where do you get off blowing up the moon? We got rights, you know! Call us irresponsible! We're just defending ourselves!"

The ominous air suddenly disappears. "Of course, I know that. " The teacher's face turned orange with a circle, "I'm not calling you irresponsible for trying to kill me. No, no, no." He starts praising Nagisa, "As a matter of fact, Nagisa here gets full marks for technique. His composure was simply outstanding. However!"

He also reprimands Terasaka, Yoshida, and Muramatsu, "None of you cared for his well-being. Not even Nagisa himself it seems. Students like that aren't fit to assassinate anyone." His face turned purple with an "X" to emphasize his point. "You must believe yourself worthy of your target and take pride in what you do, and each other. All of you are more than the sum of your parts." 

Nagisa notes that being chewed out at Mach 20 and then praised with waving tentacles, this unusual education is growing on him. When one spends their whole life being invisible, it's something to feel like you're being seen.

The teacher notices a piece of sizzling wood on his desk and thinks back. He is in a decimated building, holding a bleeding woman and telling him that she wants him to teach the children. That with those incredible tentacles of his, he'll surely be an excellent teacher. He then puts the wood out and asks Nagisa a question: "Given that I have no intention of being killed; what exactly are you going to do about it?"

'That's the big question?' Nagisa notes that they've never assassinated someone before and that there's plenty of other stuff they should be doing. Still, he feels that even the teacher will accept his bloodlust. 

"I think you'll find out I can do plenty, sir." Nagisa tells his teacher, "Just wait and see."

The teacher has his mocking face on, "That's the spirit! No one leaves until I vanquished!"

Y/n begins thinking about how their teacher is unkillable, "Korosensei..." 

"Huh?" Nagisa looked at Y/n who nodded, "It's similar to unkillable, and since we don't have a name for him, why not Korosensei?"

"You know what?" Nagisa thought about it before smiling, "I like that."

"Yeah. Makes sense since we have to kill an unkillable teacher," Kayano clapped her hands in agreement as Nakamura nodded, "Then it's settled, our teacher is Korosensei."

"And we'll kill him here, in our Assassination Classroom."