Assassination Classroom Cast and Characters

The film opens with the Japanese military's failed attempt to capture whoever it is that has destroyed half of the Moon, which sees the death of the entire squad sent to capture it. Meanwhile, Nagisa Shiota, a ninth-grade student of Kunugigaoka Junior High School, narrates of how he came to be sent to the situation he is in: he is included in Class 3-E, which is reserved for delinquents and other undesirables of the school and is a laughing stock among the school. However, Class 3-E is actually a cover up for the Japanese government in their attempt to assassinate Koro-sensei, a tentacled creature apparently responsible for the Moon's destruction. The students have to assassinate him before graduation using either a special knife or BB pellet, the time when he plans to destroy Earth, but at the same time also have to study both academic and assassination disciples from him. In teaching, Koro-sensei is assisted by the government-affiliated Tadaomi Karasuma and Irina Jelavić, a Serb assassin.

Despite being fully aware that he is their ultimate target, Koro-sensei is able to bond with Class 3-E, who in turn regard him as their indispensable teacher. When asked why he took the job, he says it is done to fulfill a promise made to someone. Throughout the school term, Class 3-E welcomes three additional students: Karma Akabane, who has recently come out of his suspension due to protecting a former Class 3-E pupil from being bullied by Class 3-A students; "Ritsu", an AI-box displaying the form of a girl; and Itona Horibe, the also-tentacled self-proclaimed "blood brother" of Koro-sensei who is carried away from the school by his cloaked guardian after losing a match against the latter. At one time, Karasuma's position as P.E. teacher is briefly replaced by his rival, Akira Takaoka, a drill instructor-esque individual. He is challenged by Karasuma, who successfully sends Nagisa to threaten him, thereby expelling him from the school.

Before the finals, Koro-sensei promises that the top scorers of the five academic subjects (Chemistry, English, Home Economics, Japanese, and Maths) will be awarded chance to cut his tentacles, which will greatly slow him. When the results for the finals are out, three students are able to jointly top the Home Economics test, thus granting seven students the chance to cut the tentacles. The students plan the killing during the summer holiday, where they reminisce about their kind past teacher, Aguri Yukimura. Eventually, Class 3-E manages to bind Koro-sensei thanks to Nagisa's observation of his weakness: water. However, Koro-sensei transforms into a ball to avoid being killed. Suddenly, the class is interrupted by a vengeful Takaoka, who poisons several students. He agrees to trade the antidotes for Koro-sensei.

Nagisa and Karma team up to incapacitate Itona, now working for Takaoka, by luring him into open rain and subsequently cutting his tentacles. However, they are alerted by Ritsu that Takaoka has kidnapped Kaede Kayano and threatens to kill her unless Koro-sensei is handed over. With a trick, Class 3-E turns the table over and defeats Takaoka without giving in. Seeing that Koro-sensei is vulnerable, the government takes him and proceeds to do a public execution in front of his grieving students. However, he manages to survive the attempted killing and is allowed to continue teaching Class 3-E for the next term, with Itona now enrolling permanently. Koro-sensei then reminisces about the person he made his promise with: Aguri Yukimura.

Ninomiya Kazunari as Korosensei

Ryosuke Yamada as Nagisa Shiota

Masaki Suda as Karma Akabane

Maika Yamamoto as Kaede Kayano

Seika Taketomi as Rio Nakamura

Mio Yuuki as Yukiko Kanzaki

Miku Uehara as Manami Okuda

Kippei Shiina as Tadaomi Karasuma

Kouki Osamura as Taiga Okajima

Takumi Ooka as Ryunosuke Chiba

Saki Takahashi as Hinata Okano

Yuuhi Kato as Yuuma Isogai

Kang Ji-young as Irina Jelavić

Anmi Okuma as Kirara Hazama

Jitsunori Uehera as Manami Okuda

Kanon Miyahara as Kataoka Megu

Ken Sugawara as Terasaka Ryoma

Yuji Takao as Takuya Muramatsu

Rena Shimura as Hinano Kurahashi

Titi Hasegawa as Taisei Yoshida

Arisa Sato as Toka Yada

Tanaka Nichinan Ayano as Hayami Rinka

Ryunosuke Okada as Maehara Hiroto

Shota Arai as Masayoshi Kimura

Ozawa Guami as Sosuke Sugaya