Yay! Ansatsu Kyoushitsu!! My favorite manga!! (Beside Ao No Exorcist) Please enjoy! And this is following the manga. For this scene, you'll be wearing the white button up shirt, the tie, the skirt and the beige sweater. (Like the one Rio Nakamura is wearing.) 

The classroom is filled with quietness as the monster walks in, places the attendance down with a light thump, and he says, "We'll start homeroom now. Whoever is on day duty, issue your commands!" Just then the boy with the light blue hair, the one you had a crush one since this year, shouts, "Stand!" And with that one word, everyone's up and pointing their guns at the monster, you gulped your spit and started to slowly sweat. As the boy commands, "At attention!" because of the girl sitting in front of you, a petite girl named, Manami Okuda. You had to stand on your desk and chair because you didn't want to hit the girl by accident so, you placed your left foot on your desk, as you balanced your self on the chair and aimed your pistol, he grins more widely. The only thoughts that could be heard bouncing from the classroom walls were, "We are professional killers." The boy with light blue hair, gulps and yells one last command, "BOW!" And the shooting of the 'Anti- sensei bullets' started to fly towards the Mach-20 monster. Using his speed, he moves from side to side, stating, "Alright! Seeing as you all are shooting, I will take attendance. Isogai-kun!" All your ears can pick up are bullets being fired and hitting off the walls. "I'm sorry, but as we are in a midst of gunfire, can you please speak up?" he says over the gun shots. "H-Here!" you finally heard and it continued from there. Later coming to your name, "Here!!" You yelled over the noise as you shot your bullet. In the end, his faces blazes a circle, and proclaims, "No absences. How wonderful! Sensei is very pleased!" Thoughts such as "He's way too fast!" and "It's no use even if the whole classroom were to shoot together." As you sighed, and took off your eye protectors, your target is your sensei, which is the yellow octopus, who continues, on with, "What a shame! There were no direct hits today either. Tactics which rely on numbers lack individual thoughts. Each and everyone is far too simplistic. Your gaze, the direction of your guns. The movement of your fingers. Devise more of a plan or else, you won't be able to kill me with my maximum speed of Mach 20." Someone in your class E starts to complain but all you did was stare at everyone, and as they all agree, and point their fingers at the teacher. Soon he says, "Load that gun and pass it to me." he gets a hold of the gun, and says, "I told you didn't I? These bullets are harmless to humans, but to me," And he pulls the trigger with no hesitation, as his blood spills and his tentacle falls. The ringing of the bullet vibrates through the whole room as his tentacle twitches. He goes on to say something, but you slowly stood off the table and chair. You collected the bullets on the ground. As he finishes his sentence you threw the handful of bullets directly at sensei, missing everyone else. Of course he dodges them all and waves his recovered tentacle at you, "(Y/N)-SAN! It's rude to throw things when I'm talking." You nodded and mumbled a sorry before he says, "You all should be able to kill me before graduation." As his face turns into striped green lines across his face, he tells everyone to clean up. Sugino goes around handing out brooms, as he hands a broom to you, he asks, "Any luck, (Y/N)?" You shook your head, "Nothing. Sorry Sugino. But you can talk to Nagisa-san. Heard that he has taken some notes. Think that will help you?" He nods, "Let's go talk to him after school." You nod before he walks away, with the broom in your hand, you started to sweep the bullets. 'We are Room 3-E of Kunugigaoka Junior High School, an assassination classroom.' Class soon began to start. You started to tune in to what sensei was teaching and took notes. When sensei decided to ask Kimura a question when you looked out to foresee the future of the world. The crescent moon. You see Nagisa and Kayano whispering to each other and that's when you felt that stomaching twisting intensity and decided to just stare at your notes. Then you remembered the day when your sensei came. 'Nice to meet you all, I was the one that blew up the moon. I also plan to blow up the Earth next year. Seeing as I will be your homeroom teacher, I am looking forward to teaching you all.' And remembering the words you said, the words that the WHOLE class said together in their heads as they sweat dropped. 'LET US TSUKKOMI IN ABOUT 5 OR 6 PLACES.'  The man beside him introduced himself as 'Karasuma' and saying, "I want you to kill this monster."You remember laughing out loud by accident and apologizing quickly after. As everyone else stared at him wide-eyed. Mimura then asks, 'Um ,er. What? So that guy is an alien who came to attack us?' He then shakes his tentacles proclaiming that he was born and raised on Earth. 'That's just making him even more mysterious.' And then remembering as Karasuma pulled out a green knife. And trying to stab him, saying, "An assassination." And remembering, that Karasuma's eyebrows were trimmed and nicely done. Then the sound of a gun shot ringed, "Nakamura-san!! Don't interrupt my class! As punishment, you have to go stand at the back of the class!" She sticks her tongue out and reply, "Sorrry! You don't have to turn red when you're angry!" As she trudges to the back of the class, you remember, the over-whelming prize, 'If you are successful, you may be able to gain 10 billion yen.' The eyes of everyone brighten up, then Karasuma goes on to say, that is was an appropriate sum to gain since the success of the assassination is the Earth's salvation. And remembering one solid information, his face turning into green stripes, he's mocking. And remembering that he does high-maintenance. While mocking everyone by saying that even the government couldn't kill him. Thoughts were soon stopped short when the bell rings signalling for lunch. And then using his Mach 20, he decided to fly to China. And left his students in the dust of the classroom. Everyone then disperses while complaining. You sat at your desk, and listened to their complaints as you stand up with your lunch in your hand. You walked out into the sun and sat down by the steps. And leaned your head to your knees. And held them close as you sighed. 'How are we suppose to kill the damn octopus?' We aren't just regular students anymore either, we are assassins. Just as you were about to eat, 4 guys walked out. 3 big guys, Ryoma Teresaka, Takuya Muramatsu, and Taisei Yoshida. The fourth figure was none other than your crush, Nagisa Shiota. Teresaka stares at you as you stare back at him, "Hey, little girl, move." You stared at him a little more colder and picked up your stuff. You were walking past the boys when Nagisa grabs your wrist and whispers, "Sorry, thanks." And you nod, and continue to walk as Nagisa's hand slips away from your wrist. You walk back to class and sat at your seat, holding your wrist. "Heh, he held my hand." You mumbled to yourself before looking up to see Sugino walking to you, you took your lunch out, and sipped your juice. "Hi, Suguino. Is there something you need me to figure out?" He shakes his head, "I was wondering if you know where Nagisa went, I think I could ask him now instead of after school." You reply back, "He's out in the front with Teresaka and his gang, I think he's busy." You look outside and said, "They're probably planning an assassination." He nods, "Okay. You're still helping me right? Tomorrow morning?" You nod with a smile. "Yea." He smiles back with a thumbs up, "Thanks. We'll meet after school today." You ate your lunch quickly and looked out to see sensei with Nagisa, talking and Nagisa hiding... something. Soon sensei walked away leaving Nagisa outside. You stared at him longer and see the mood around him change. His face hidden from thinking. 

Timeskip: 

"Let's try writing Tanka poem this time." He goes onto talk more and gave an example. "Please end it with tentacles with the last 7 syllables." And everyone is stuck, all you did was think about food. "Sensei! I have a question." As they discuss about sensei's name. You sense something in the front, so you quickly wrote, 'My thirst for something. Like something is missing bad. Takoyaki-kun. It is missing in my life. It is made from tentacles.' You weren't even sure if that's true or not, but you were hungry and something might happen so you decided to go with it. You brought a real knife and a pencil and walked forward. You were halfway to the sensei when Kayano finishes her conversation with sensei, Nagisa stands up, in front of you. You saw the anti-sensei knife, everyone saw the knife. Everyone's breathes caught in their throats. You saw something even more interesting, a string. Probably something not good. You gulped, and stopped Nagisa. "Nagisa-kun!" His attention snaps to you, there was fear written deep in his eyes. "You picked the wrong word for this sentence, here." You used your pencil to write something around the knife, 'I'll help out.' you wrote. He looks to you, "Do you not get it, Nagisa-kun?" You push him into his seat and smiled, "Here, I'll explain." You looked at sensei from the corner of your eye, to see him turn light pink, to show that he's tired. You smiled back at Nagisa, and slowly started to work on the tie to the string. While quietly talking to Nagisa, explaining, "Here, I'll handle the grenade, just attack him with the knife and jump back. Okay?" "Huh?" He says, as you show him the grenade, through your sleeve. "Okay, Nagisa-kun! Show him your poem!" And he goes in front of you. You can feel the intensity of the class as they can see the knife. As Nagisa goes in for the kill and sensei dodges it, he then laughs, "Too slow." You jump and grab sensei, pulling the grenade out and soon enough, someone has the controller and everything explodes. 

Kayano's P.O.V: 

I watched intensely as Nagisa and (Y/N) walk, I watched with my throat all dried up, as Nagisa's knife is resting behind the paper. I watched as (Y/N) walk with something bulging from her sleeve. I just stared as Nagisa approaches sensei, and pull the knife. My breathe trapped in my chest, as I witnessed as (Y/N) grabbed sensei from behind and held a green item in her hand. Everything exploded before my very eyes, of course I looked away. Soon when everything dies down, Teresaka burst out into laughter and screamed, "ALRIGHT!! WE DID IT!!" I just stood there, as I saw him walk to the front, "Well, even though Nagisa didn't do it, whatever. 10 MILLION YEN IS OURS!!" He roared. I yelled at him, "What was that?! What did you make Nagisa carry that soon (Y/N) took?" He goes on to explain, that it was just a toy grenade, powered with gun powder. I stood there in shock, he continues to say, "In order  to shoot 300 anti-sensei bullets at a high speed." "Wha!" My jaw dropped, he tried to risk Nagisa doing that and caused (Y/N) -chan's life instead?! As I was about to yell at him, "It ain't enough to kill a human, with 10 million yen, I'll cover Nagisa, (Y/N) can cover herself, since she's rich! As I look over to expect 2 very severally injured bodies, instead I see Nagisa and (Y/N)-chan under a sheet of something. Teresaka stares in anger, to see that his plan didn't work. Nagisa soon woke up, but (Y/N)-chan still hasn't awaken yet. Her eyes were twitching, but they weren't opening, "(Y/N)! Wake up!" My cries were wished when her eye open for sure, but her eyes bare no color. She sits up, wavering just a little. She looked around but doesn't comply. Is she alright? 

Back to you: 

Your thoughts aren't working, you can't see any color, just black and white. Your hand reaches to the blanket or something. And looked around, your ears are still ringing. 'How did Nagisa take it?', you thought as you looked over to see Teresaka and his gang. With fear in their eyes as they point to Nagisa, Nagisa is sweating. Soon, you look over to sensei's face to see it pitch black, distorted, it's really ugly and dangerous. But you can't hear what he's saying. Color is finally returning to you, the first color that came to you was blue, you were able to see Nagisa's hair and eyes. As sensei is away currently, Nagisa looks over to you, and whispers, "Are you okay, (Y/N)-san?" Before you reply, sensei comes back. With the name plates of all your houses, you just stared as you slowly regained your hearing. "...... any of you, but, if you come to kill me next time with the same method, I don't know what will happen with the ones that isn't you! Your friends and family, no.....  I kill everyone on Earth but you. In the whole thing that was only five seconds, your heart started to tremble, everyone wanted to leave. We all understood if we want to escape, we can't even fly to the other side of the world, we need to kill him! Teresaka then starts to yell at the sensei and point his finger at him, calling him irritating and even going as far as going to say that his plan was irritating. That seemed to calm sensei down to the point at least he had the correct face. He turned to Nagisa and gave him a smile and congratulated Nagisa for his efforts. This seemed to enlighten Nagisa's mood and made him look extremely cute, he turns to you. And say, "Great work, (Y/N)-san! You did amazing too, your talking and actions seemed a little forced, however you attacked well too. Good job." He turns to Teresaka and his gang, to say, "However, Teresaka and the others, you both did not consider Nagisa's welfare. Nor (Y/N)-san," he looked to me, "However, I am aware that you knew this at that moment." He turns back, "Still, students with that do not have the right to kill me. " He faces the class and says, something but your hearing blacked out for a second only to hear, ".... as a target." You blink for a few seconds, and looked over to Nagisa to see him dazed and staring at sensei as sensei's looking at his table. His tentacle slowly wiggles over to the desk and places his tentacle delicately with a smiling face but a hurt atmosphere. You tightened your lips and then he asks Nagisa, "........ what will you do?" You look to Nagisa to wait for his answer, and you notice him clenching his fist. "Before that happens, we'll kill sensei!" "If that's the case, please kill me, to those who can kill me they can go home." And he cleans our home plates as you stand up, Nagisa walks to you and bends over,"You okay, (Y/N)-chan?" You smiled, "Yea, oh!" You grab Nagisa and said, "Sorry!" And with that you walk back to your seat you sat down and held your pistol. Kayano mumbles to herself, and came up with the name, "Koro-sensei for unkillable, and teacher." You sighed sharply, "We'll never be able to kill him." 

Soon enough:

'Koro-sensei' gave a heart and allowed us to head home. As you pack up, Sugino taps your shoulder and you look over, and nodded. You grab your stuff and walked with Sugino over to Nagisa. "Hey Nagisa, do you have a moment?" Sugino asks. Nagisa smiles, "Yea." You, Sugino and Nagisa head down the mountain, Sugino asks Nagisa. Later, you all split up and as you head home, you laugh. "Just wait, Koro-sensei!" As the sun sets, tomorrow's bell will sound tomorrow as well. 

Thank you all for reading the first chapter. Please rest assure that I will update!