[[quoteright:250:http://static.tvtropes.org/pmwiki/pub/images/rsz_70623l_3253.jpg]]
[[caption-width-right:250:Just another day in class 3-E]]


The story is about class 3-E of Kunugigaoka Middle School where every morning they greet their sensei (named Koro-Sensei) with a massive firing squad. The sensei is a weird combination of an alien and an octopus that moves at speeds of mach-20. It turns out this creature was responsible for the destruction of the moon, rendering it forever in a crescent shape. He has announced that he will destroy the world in one year. The creature will teach class 3-E how to assassinate him before the year is over. But...he's the best teacher they've ever had.

Imagine {{Great Teacher Onizuka}} mixed with sci-fi and espionage to get an idea of what you're in for. The series creator is also the creator of {{Majin Tantei Nougami Neuro}}, which deals with similar ideas, mainly a supernatural creature with {{Blue and Orange Morality}} who's ultimately bettering the people it comes across. The difference is where Neuro was protecting his food source, Koro-Sensei is trying to better his students by working in the killing arts as a teaching tool. [[CrazyEnoughToWork And it works]]. Course there is the problem of him planning to destroy the world...

Ansatsu Kyoushitsu is currently serialized in Weekly ShonenJump.

The [[Characters/AnsatsuKyoushitsu character page]] is in the development stages.

!!This series provides examples of:
* TheAce: Karma in regards to class E, Koro-Sensei for the entire series.
** [[spoiler: Nagisa]] when it comes to assassinations, surprisingly enough.
* AffablyEvil: For a man who wants to destroy the world, Koro-Sensei doesn't act like it.
** FauxAffablyEvil: Takaoka.
* ArcSymbol: The crescent moon on Koro-Sensei's tie. It's often used as a reminder of just how powerful Koro-Sensei is.
* AppliedPhlebotinum: The guns, grenades, knives, swords, etc. used by the students are made of a specially made substance harmless to humans, but on contact will cause Koro-Sensei's cells to break down.
* AssassinOutclassin: Naturally, or the Series would be over before hitting the third page of the first chapter.
* ATeamFiring: The opening of the story begins with the entire class trying to gun Koro-Sensei down. Not only does this fail, but Koro-Sensei continues as if nothing were happening, taking attendance as the class continues shooting. The only notice he takes is when he asks a student to speak up, since he can't hear well over the gunfire.
* AxesAtSchool: They're rubber knives and pellet guns that are only harmful to Koro-Sensei, but they're still rather alarming.
* BadAss: Karma. He is the very first student to actually inflict damage on Koro-sensei as well as causing him to (momentarily) lose his cool.
** Karasuma is also a wonderful example, apparently scoring a full 100 in "fighting" by the assessment of [[spoiler:Irina's assassination master]]. And then there's his attitude, which is also undeniably {{Badass}}.
* BadassBoast: After blowing off Korosensei's index finger, [[spoiler:the AI]] delivers this.
-->'''[[spoiler:AI:]]''' The killing probability of the next shot is less than 0.001%. The killing probability of the shot after that is less than 0.003%. The probability that I'll be able to kill you by graduation is more than 90%.
* BeautyEqualsGoodness: If you're attractive without looking downright creepy, then you're likely a member of Class-E in one way or another. The only exception to this seems to be Koro-sensei and the three Class-E bullies. It's even lampshaded when two girls in a higher-ranking class note that Class-E's phys ed teacher, the young government agent Tadaomi, is rather attractive, and that all of the guys and teachers in their class are ugly and mean.
** Averted with Tsuchiya Kaho of Class C. Beautiful? Yes. [[{{Jerkass}} Cold-hearted, manipulative, vile witch]]? An undisputed affirmative.
** PlayedWith Takaoka: his cartoony (well, more cartoony) smiley face masks a vicious streak a mile wide.
* BerserkButton: When Bitch-Sensei calls Class E "Misfits of the school" and tells them studying would be meaningless, she gets pelted with school supplies by the whole class.
** Also Koro-sensei if anyone tries to hurt his children. Usually though[[spoiler: he just 'beautifies' them, calling it 'performance'. Then again, he also called it performance when he beat up several wannabe-kidnappers...]]
** When he saw [[spoiler: Horibe Itona's tentacles]], his face goes Pitch Black, Extreme Anger.
* BizarreAlienBiology: Plenty with Koro-sensei, from his [[ColorCodedForYourConvenience color-changing face]] to his [[SwissArmyAppendage multi-purpose tentacles]], with more quirks being revealed over time.
* BlatantLies: When higher-ranked students harass Nagisa because they didn't like how happy he seemed, they corner him. When he doesn't seem threatened or bothered by him, they threaten his life. All it takes is a non-threatening WhamLine and a DeathGlare on Nagisa's part to scare them off. Then they go and tell everyone that ''they were the ones giving a death threat.''
* BreakingTheFourthWall: In Chapter 22.
-->''Takebayashi, do you seriously want that to be your first line in this manga?!''
* BunnyEarsLawyer: Koro-Sensei, despite his appearance, despite being a god-like superbeing capable of destroying planets... is actually a really great teacher.
* CastOfSnowFlakes: No two major characters look alike.
* ColorCodedForYourConvenience: Since Koro-Sensei is almost always smiling, his emotions are read by his face's coloration and color pattern. The most notable is Pitch Black, Extreme Anger.
* CombatTentacles
* CrazyPrepared: Koro-Sensei's [[GreatBigBookOfEverything guidebook]].
* {{Crossover}}: A one chapter story with ChounouryokushaSaikiKusuoNoSainan.
* CutlassBetweenTheTeeth: Nagisa holds a combat knife with his mouth so he can limber up before he fights [[spoiler: Takaoka]].
* DefaceOfTheMoon: Koro-Sensei's first major demonstration of power: he basically reduced it to a permanent crescent.
* DissonantSerenity: Takaoka's always grinning, whether he's handing out pastries, revealing his ridiculous training schedule, or violently attacking contrary students.
** [[spoiler: Nagisa]] is capable of this [[spoiler: as he's remarkablt talented in controlling his bloodlust.]]
* DrillSergeantNasty: Takaoka Akira. Has a "10-sticks-to-one-carrot" philosophy, is more like a dictator than an officer, and "accidentally" leaves a picture of the soldiers he's tortured in front of Tadaomi. ''And he's always smiling''.
* EldritchAbomination: Averted. Even though Koro-Sensei looks like a freaky alien octopus, he states that he was born and raised on earth. As what, human, animal, vegetable, or mineral, is anyone's guess.
* EmbarrassingNickname: Irina Jelavic gets two rather funny ones from the students after she insults them. 'Bitch-Neesan' and 'Bitch-Sensei' after she finally (sort of) wins their approval.
* TheEndJustifiesTheMeans: The Principal makes Class E the school's pariahs because it means the other students will do anything to keep their grades up and not get sent there.
** Takaoka's extremely harsh (if not downright impossible) training schedule will be worth it if just one student survives and succeeds in killing Koro-Sensei because ''Takaoka'' will become famous for training the assassin and then [[TheRival Tadaomi]] will finally acknowledge his superiority!
* ExcuseMeWhileIMultitask: When people try to kill Koro-Sensei he's usually doing other things, such as meticulously trim his attackers eyebrows or give a fighter jet a polish in mid-air. See also the example from ATeamFiring.
** MesACrowd: He can move so fast he can make selectively tangible afterimages. Chapter 12 shows him making one for every student in the class to personally focus on their weak subjects. [[RefugeInAudacity He even leaves one outside]] to rest from all that work.
* EvenEvilHasStandards: Koro-sensei is not pleased when one of his students' collaborative attempt at killing him almost injures one of their own.
** The other students' treatment of Class E at the assembly appalls even Irina-sensei.
* EvilRedhead: Karma, [[HeelFaceTurn at least at first.]] (And for a given definition of evil.)
* AFatherToHisMen: How Takaoka sees himself. The torture and possible mind-rape is just fatherly discipline!
* FlashStep: Koro-Sensei has a top speed of Mach 20. During one assassination attempt, he easily dodged the attacker while [[CrazyAwesome meticulously trimming his attacker's eyebrows.]] When attacked by state of the art fighter jets, he gave them a mid-air waxing. When attacked by knife armed students, he disarmed all of them, then replaced the knives with tulips without their noticing.
* ForcefulKiss: Irene does a 30-hit combo one to Nagisa at one point before telling him to meet her in his office so they can discuss Koro-sensei's weaknesses.
* AFormYouAreComfortableWith: Debatable, but the first chapter makes it clear that his current appearance is not his true form. Surprisingly, sans tentacles, his shadowy true form seems human-like.
* {{Foreshadowing}}: Nagisa is being built up to have a ''lot'' of hidden talent.
** [[spoiler: Confirmed in Chapter 41 which reveals that Nagisa has an ''exceptional'' talent for assassination.]] To be specific, his ability to [[spoiler: hide such bloodlust that it scares trained soldiers.]]
* GameFace: Koro-Sensei's Black Face. When it turns Black, it is ''on''.
* GettingCrapPastTheRadar: Erina Jelavic's introduction for one. What Korosensei does to her is another.
* GreenEyedMonster: Takaoka Akira was incredibly jealous of Tadaomi, as Tasaomi was the most talented member of their unit in the JSDF and quickly rose above him. He hopes that if he turns Class E into the heroes who will defeat Koro-Sensei, then he'll also become a hero, and finally be able to order Tadaomi around.
* HealingFactor: Koro-Sensei, amongst other abilities, has the power of regeneration. Even if he gets hit with the AppliedPhlebotinum weapons, unless his body is almost completely destroyed, he'll recover in seconds.
* HiddenDepths: Nagisa is heavily implied to be more than just the main perspective character, as evidenced by his training with Tadaomi in chapter 38. Tadaomi has the kids attempt to attack him with their anti-Koro-sense knives, which are harmless to humans. Suddenly, a monstrous snake attacks Tadaomi. This is later revealed to be some sort of hallucination he had, and it was actually Nagisa. [[spoiler: Later, when Takaoka challenges the class to fight him with ''real knives'' (believing that, like his other recruits, they'll choke because they've never used a real weapon), Tadaomi gives the knife to Nagisa.]]
* HoneyPot: One of Irina's favorite tactics before she came to Class E.
* IdiosyncraticEpisodeNaming: So far all of the chapters have the word "time" in them.
** Possibly intended as a reminder that there is a deadline for how long the students have left to kill Koro-Sensei.
* IdiotBall: The principal. Suffice to say. [[spoiler: beating down the confidence of the only people in a legitimate position to end a world ending threat that will destroy ALL LIFE on the planet within a year is a terrible idea. If they fail due to, say a lack of confidence in their own abilities thanks to a systematic destruction, then he's equally culpable for the destruction of the human race in order to preserve his ideals as a teacher which favors grades over individuals. Worse, if they succeed? Then a phenomenally rich, highest quality assassin who has the favor of every government on the planet, the assistance of several of the worlds best assassins and an overtly obvious reason to HATE the principal for making their junior highschool years a living hell, has every reason to ruin/kill him with every resource available to them and basically no one to tell them not to. I mean... anyone with real authority knows they saved the world, right?]]
** HonorBeforeReason: Even if it's a [[{{WhatAnIdiot}} stupid]] version of it, at least the guy doesn't compromise his beliefs.
* ImprobableAge[=/=]YoungerThanTheyLook: Irina Sensei, as revealed in chapter 19, is only 20 years old.
* InformedFlaw: Class E is supposedly composed of the high school's worst students, but plenty of them seem reasonably intelligent.
** In later chapters, it's revealed that they're the lower 1/5 of a school that is one of the prestigious in the country. Their Class E status is not due to their being unintelligent, but having lower test scores than the remaining 80% of the school (smart enough to meet the minimum requirements to enter the school, but not enough to excel).
** Moreover, some of the students are extremely skilled in some subjects, but very weak in others (one student is very skilled in both math and science, but has failing grades in Japanese (the equivalent of western English classes)). Then, there's students like Karma, who were placed in class E as a disciplinary action.
* InvoluntaryShapeshifter: Koro-Sensei transformed several times after drinking hazardous chemicals.
* JerkAss: '''EVERYONE''' who isn't in Class-E, and several students who are. The school's chairman gets special mention, because he specially designed the school to encourage its students ''and teachers'' to be this way to everyone associated with Class E. Seriously, if this weren't a manga, a good half of this school's faculty would have been canned ''long'' ago in any country with a reasonable education system.
* JerkWithAHeartOfGold:
** Koro-sensei, who will destroy the world, but also ensure that his students get good grades and become successful.
** Karma, who is initially introduced as an AxeCrazy lunatic, but is later revealed to have been a BullyHunter and an excellent student. What landed him in Class-E wasn't his being evil, but siding with a Class-E student who was being bullied.
** Irina. She initially doesn't care about the students or believe in them, but she grows to care for them and increasingly become disgusted by the school's system of degrading Class-E.
* [[KaleidoscopeEyes Kaleidoscope Face]]: Koro-sensei.
* LaserGuidedKarma: Whenever the higher-ranked students are shown to look down upon or make fun off Class-E students, Koro-sensei helps them to get their revenge or something eventually happens to make them regret it, unless the [[KarmaHoudini Chairman]] appears to intervene.
* TheMessiah: For a creature who intends to destroy the world, Korosensei is an expert in making people change their ways for the better. Karma, Irina and "Red Eye" are all examples of this charisma and wisdom Korosensei possesses, along with his interactions with all of Class-E. He might as well be Buddha. [[spoiler: Considering what Asano said about Korosensei "intending to become the world's savior", perhaps there is cause to this.]]
** "If you meet the Buddha, kill him"?
* MsFanservice: Irina Jelavic.
* MysteriousPast: Koro-sensei. Why did he choose to become teacher of Class-E? Who is the woman to whom he made that promise? Where did he come from? What is he? These are just the first questions that come to mind.
** When the Chairman takes the time to see him personally, he drops a HUGE hint: [[spoiler: he says that Koro-Sensei was created to save the world, but wound up becoming its greatest threat.]]
** Karasuma makes mention of another one: at one point in the past, Koro-sensei only had two legs and two arms. This was not the case in the flashback with the woman he made his promise to. In short, Koro-sensei might have once been Human.
** On the other hand [[spoiler: the students conclude that both Koro-sensei and Itona are artificial beings, with Itona being made after Koro-sensei]].
* NewTransferStudent: Introduced in chapter 20. [[spoiler:The "Student" is a [[MoreDakka gun packing]] AI.]]
** The second one is introduced at the end of chapter 28. [[spoiler: [[WhamLine The "Student" is Korosensei's BROTHER.]]]]
* NiceGuy: Tadaomi, the government agent assigned to overlook the class and help sharpen their assassination skills, only wants to save the world while ensuring that the kids are both safe and successful in their classes. He generally keeps calm about it, but is ''not'' pleased with the Chairman's school system.
* NonStandardCharacterDesign: Koro-sensei and the Chairman both look quite distinct from any other character. Most characters are your basic anime designs, drawn with rounded lines and uneven hair. It goes without saying that Koro-sensei, being a tentacle monster, has a unique entirely rounded appearance. The Chairman is more subtly strange, but his design also feels off compared to (other) humans. He is incredibly angular and sharp-looking, and his clothes have noticeably fewer creases and wrinkles. The contrast between the two is probably intentional, to match their opposing roles in the story.
* OneHeadTaller: Takaoka.
* TheOnlyOneAllowedToDefeatYou: The students come to this decision after [[spoiler: Itona almost kills Koro-Sensei and they feel it's not "right" for a stranger to kill their teacher]].
* OnlySaneMan: Tadaomi.
* PrehensileHair: [[spoiler:Itona's tentacles.]]
* ThePromise: Koro-Sensei is teaching the students in his class as a promise he made to someone. As he once put it, teaching all of his students seriously is much more important to him than the end of the world.
* {{Pun}}: Tons. Of particular note, Koro-sensei's name was chosen for him by the class for sounding similar to "korosenai," the potential-negative form of the verb meaning "to kill," so it means "cannot kill" or "cannot be killed."
* InsaneTrollLogic: The Chairman of the school is more interested in preserving his system than ''keeping Koro-sense from destroying the world.''
* RagtagBunchOfMisfits: Class E.
* ReasonableAuthorityFigure: Tadaomi, who cares just as much for making sure the Class E students can overcome the chairman's system as he does keeping them healthy and safe while making sure they can stop Koro-sense from destroying the world.
** Koro-sensei doesn't seem like this at first, but is soon revealed to be one.
* RecycledInSpace: It's ''GreatTeacherOnizuka''. With an alien.
* TheRival: Takaoka was this to Tadaomi in training.
* SadistTeacher: Takaoka Akira. He's more akin to a drill sergeant than a teacher, instituting a ''ten period'' class schedule, most of which consists entirely of training, and isn't above smacking any disagreeable student ([[WouldHitAGirl girls included]]) around.
** The chairman.
* SensualSlav: Irina, a very seductive assassin.
* ShoutOut:
** When wearing a headband for each student showing their weak subjects, he wears a {{Naruto}} Headband for a student that's bad in many.
** When Irina starts teaching the kids how to speak in foreign languages, basing her lessons around her experience in seducing foreigners, a female student pictures [[Franchise/PiratesOfTheCaribbean Jack Sparrow]] and another student pictures [[VideoGame/TombRaider Lara Croft.]]
** In chapter 16, there is the [[http://static.guim.co.uk/sys-images/Guardian/Pix/online/2012/8/22/1345647849262/Ecce-Homo-by-Elias-Garcia-006.jpg Botched Ecce Homo Painting]].
** When Red Eye is reminiscing about past missions, one of his victims is [[SesameStreet Elmo]]. [[SuperMarioBros Mario's hat]] appears in the same panel.
** Irina makes Class E watch ''Series/SexAndTheCity'' for English lessons.
** When Irina's master is talking about understanding differences in power, the character chosen to represent this concept in silhouette is a slightly altered but still clearly recognizable [[{{Pokemon}} Mewtwo]]
** [[spoiler: Itona's "handler" Shiro]] wears an [[spoiler: anti-Sensei fabric]] outfit with an upside-down version of [[ComicBook/{{Watchmen}} Dr. Manhattan's]] hydrogen symbol.
** When musing over the fact that he [[spoiler:has a brother]], Korosensei briefly envisions himself as Raditz and [[spoiler:his brother]] as Goku.
* SlasherSmile: [[http://mangafox.me/manga/ansatsu_kyoushitsu/v01/c001/39.html Pitch Black.]] [[OhCrap Extreme Anger.]]
* SuperSpeed: Koro-Sensei, as previously mentioned, can move at Mach 20. He eats shaved ice he personally gathers from the North Pole. He eats Chinese food on his lunch break... in China.
* SupportingProtagonist: Nagisa. From chapter 1 onward, he's been making note of every weakness his sensei has, from the weak, like Sensei's preference for large breasts, to the strong, like [[spoiler: his reduced stamina after regenerating a wound.]]
* ThereWasADoor: How Itona enters Class E.
* ThisWasHisTrueForm: [[spoiler: It hasn't happened yet, but in Chapter 32 there's a panel that implies this will happen to Korosensei when he is killed.]]
* {{Tykebomb}}: [[spoiler: A young boy who has powers similar to Koro-sense transfers into the class in order to kill Koro-sensei. His handler also follows him in because he's rather AxeCrazy.]]
* YouGottaHaveBlueHair: Nagisa, though he and Kaede are pretty much the only ones with unusual hair. Everyone else has normal colors.
* WeakButSkilled: Akira notes that Nagisa is amongst the weakest of the boys, with physical stats closer to that of a girl's. A few pages later, Karasuma is staring at Nagisa in awe as [[spoiler: he managed to take down Akira in a matter of seconds]] and noting that Nagisa's talent never would have been discovered in the course of a normal school life.
* WouldHurtAChild: Akira is not above hurting disobedient students. The chairman is an emotional variant of this.
* YoungerThanTheyLook: Irina Jelavic is only 20 years old.
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