Assassination Classroom
Manga by Yusei Matsui (2012–2016, 21 volumes). A mysterious supernatural creature called Koro-sensei, who destroyed 70% of the Moon, becomes homeroom teacher of Class 3-E at Kunugigaoka Junior High School. Students have one year to assassinate him or Earth will be destroyed.
- Genre:
- 学園 / アクション / コメディ / 少年漫画
- Medium:
- Manga / Anime / Film
Assassination Classroom — Timeline20 events
70% of the Moon Is Destroyed
A mysterious creature destroys 70% of the Moon, leaving it permanently crescent-shaped. It declares to world governments that it will destroy Earth the following March, and proposes to serve as homeroom teacher for Class 3-E at Kunugigaoka Junior High School while allowing assassination attempts. Governments set a 10 billion yen bounty and secretly delegate the mission to the students.
— Chapter 1, volume 1. The in-universe 'present' is unspecified but set in fictional contemporary Japan.
Koro-sensei Joins Class 3-E as Homeroom Teacher
The yellow tentacled creature officially arrives as homeroom teacher for Class 3-E. Student Kaede Kayano dubs it 'Koro-sensei' (meaning 'unkillable teacher'). Class 3-E occupies a dilapidated hilltop campus, and students begin assassination training alongside regular lessons.
— Chapter 1. The name 'Koro-sensei' is coined in the opening of chapter 1.
Ministry of Defense Agent Karasuma Joins as P.E. Teacher
Ministry of Defense special agent Tadaomi Karasuma joins Class 3-E as a physical education teacher, beginning formal assassination training for the students. An elite combatant, Karasuma oversees the students' physical development and serves as the government's liaison.
— Chapters 3–4. Karasuma's arrival is in the middle of volume 1.
Karma Akabane Returns and Nearly Kills Koro-sensei Solo
Genius student Karma Akabane returns from suspension and joins Class 3-E. Leveraging exceptional combat instinct and cunning, he single-handedly pushes Koro-sensei off a cliff but fails to kill him. His arrival significantly raises the class's overall assassination capability.
— Volumes 1–2 (chapters 5–6).
Professional Assassin Irina Jelavić Infiltrates as English Teacher
Irina Jelavić, a professional assassin specializing in honeytrap tactics, is dispatched as an English teacher. Her honeytrap attempt on Koro-sensei fails, and she remains as Class 3-E's English teacher. Students nickname her 'Bitch-sensei.'
— Volume 2 (chapters 7–8). The date May 1 is explicitly stated in the text.
Transfer Student Itona Claims to Be Koro-sensei's 'Brother'
Transfer student Itona Horibe, who possesses tentacles identical to Koro-sensei's, arrives claiming to be his 'brother.' Masterminded by his guardian Shiro (Yanagisawa), a fierce battle ensues. Itona withdraws when his tentacles go berserk, but his connection to Shiro plants a key plotline.
— Volumes 2–3 (around chapter 11).
Kayano and Kanzaki Are Kidnapped During the Kyoto Field Trip
During the Kyoto school trip, Kaede Kayano and Yukiko Kanzaki are kidnapped by delinquents. Using a guidebook secretly prepared by Koro-sensei, Nagisa and classmates mount a solo rescue operation. The incident demonstrates the class's growing independence and practical skills.
— Volume 3 (chapters 18–21).
Class 3-E Tops the School Charts in Final Exams
Class 3-E students claim multiple top-five spots across the major subjects in the first-semester final exams, breaking the monopoly held by elite Class A. The result is a milestone reflecting Koro-sensei's highly individualized teaching, reshaping how the class sees itself.
— Volumes 4–5 (around chapters 27–33).
Class 3-E Launches a Full-Scale Assassination Operation on a Southern Island
During summer training camp on a remote island, Class 3-E executes a large-scale assassination plan using anti-sensei BB pellets. Koro-sensei detects every move and the plan fails. The operation establishes the entire class as active participants in assassination planning.
— Volumes 7–8 (around chapters 50–60).
Nagisa Defeats Takaoka, Demonstrating the True Nature of Assassination
Ministry-dispatched instructor Takaoka Akira implements a regime of fear and harms students. When Takaoka resurfaces during a virus terror incident, Nagisa defeats him one-on-one, for the first time clearly establishing Nagisa's unique assassin talent — concealing lethal intent beneath an innocent exterior.
— Volumes 8–9 (around chapters 60–70).
Class 3-E Rescues Abandoned Itona; He Becomes a Classmate
When Shiro (Yanagisawa) abandons Itona as a failed experiment and his tentacles run out of control, Class 3-E rescues him. Koro-sensei removes the tentacles, and Itona is formally welcomed as a classmate, resuming ordinary school life alongside his peers.
— Volume 10 (around chapters 81–83). Around the start of anime season 2.
A New 'Reaper' Assassin Attempts to Kill Koro-sensei
A second assassin who inherited the name 'Reaper' — the alias once held by Koro-sensei's former master — infiltrates Class 3-E and launches an operation targeting students, Karasuma, and Koro-sensei simultaneously. The arc begins revealing Koro-sensei's past and his former master-disciple relationship.
— Volumes 11–12 (around chapters 88–100).
Koro-sensei's Human Past: He Was Once the World's Greatest Assassin
It is partially revealed that Koro-sensei was once human — a man called 'the Reaper,' feared as the world's greatest assassin, responsible for over a thousand deaths. He became a test subject for researcher Yanagisawa's antimatter experiments and mutated into his current form, while also forming a bond with Yanagisawa's assistant, Aguri Yukimura.
— Volumes 12–14 (around chapters 100–120). Depicted in detail in anime season 2, episode 16 'Time of the Past.'
Class 3-E Splits Over Whether to Kill or Save Koro-sensei
Class 3-E divides into two factions: assassinate Koro-sensei to save Earth, or search for a cure. Nagisa leads the 'save him' side; Karma leads the 'kill him' side. A mock battle settles the conflict, and ultimately every student chooses to spend the remaining time with Koro-sensei, resolving their internal divisions.
— Volumes 15–16 (around chapters 131–140).
Kaede Kayano Is Revealed to Be Aguri Yukimura's Sister
Kaede Kayano is revealed to be Yuki Yukimura (Akari), the younger sister of Aguri Yukimura. She had implanted tentacles in herself and infiltrated Class 3-E to avenge her sister's death. Nagisa uses his assassination talent — a disarming kiss — to break the tentacles' hold and save her. Koro-sensei then discloses the full truth of his past.
— Volume 16 (around chapters 142–145).
Yanagisawa's Experiments, Aguri's Death, and the Inevitable Countdown
The complete truth of Koro-sensei's past is disclosed: antimatter experiments pushed his body to its energy limit; Aguri Yukimura died shielding him from Yanagisawa's execution order; and he became Class 3-E's teacher to honor her dying wish. His March explosion is confirmed as biologically inevitable.
— Volumes 16–17 (around chapters 145–150).
Government Fires Orbital Laser; Yanagisawa and New Reaper Attack Simultaneously
With the March 13 deadline approaching, the government fires an orbital high-powered laser at Koro-sensei. Simultaneously, Yanagisawa — now mutated with tentacles — and the new Reaper attack. Koro-sensei takes fatal damage shielding Kayano but defeats both enemies with his remaining strength.
— Volumes 20–21 (around chapters 170–178).
Class 3-E Unanimously Decides to Assassinate Koro-sensei Themselves
With the government laser imminent, Class 3-E unanimously decides to carry out the assassination themselves. Koro-sensei delivers one final lesson, then takes roll call, calling each student's name in turn. This scene stands as the emotional climax of the entire series.
— Volume 21 (chapters 178–179).
Nagisa Delivers the Final Blow; Class 3-E Graduates
With the consent of every classmate, Nagisa Shiota drives a knife into Koro-sensei's heart. Koro-sensei dissolves into particles of light, leaving no physical remains. Class 3-E graduates in tears. Earth is spared. The one-year assassination classroom comes to its end.
— Volume 21 (chapters 179–180). Final chapter.
Seven Years On: Nagisa Becomes a Teacher; the Moon Slowly Heals
Seven years after graduation, former Class 3-E students pursue their chosen paths. Nagisa Shiota, inspired by Koro-sensei, becomes a junior-high teacher and takes on a troubled class. Kaede Kayano returns to acting and stars in a prime-time drama. The crescent moon is shown gradually restoring itself.
— Volume 21 (chapter 180, final epilogue).
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