Assassination Classroom (Japanese: 暗殺教室 Hepburn: Ansatsu Kyōshitsu) is a Japanese manga series written and illustrated by Yūsei Matsui. The series began serialization Shueisha's Weekly Shōnen Jump magazine from July 2012 and is licensed in English by Viz Media. The series follows the daily lives of an extremely powerful octopus-like alien teacher and his students dedicated to the task of assassinating him to prevent Earth from being destroyed. As of July 2015, fifteen tankōbon volumes have been released in Japan with a circulation of ten million copies.
A single original video animation adaptation by Brain's Base based on the series was screened at the Jump Super Anime Tour on October to November 2013. This was followed by a television anime adaptation by Lerche, which began airing on Fuji TV in January 2015. This adaptation has been licensed by Funimation for release in North America. The series was obtained by Madman Entertainment for digital distribution in Australia and New Zealand. A live action film adaptation was released on March 21, 2015. The series aires on Adult Swim's Toonami block this fall.
The Earth is threatened by a powerful creature who destroyed 70% of the Moon with its power, rendering into the shape of a crescent moon forever. The creature claims that within a year, Earth will also be destroyed by him, but he offers mankind a chance to avert this fate. In class 3-E at Kunugigaoka Junior High School, he starts working as a homeroom teacher where he teaches his students not only regular subjects, but the ways of assassination. The Japanese government promises a reward of ¥10 billion (i.e. 100 million USD) to whomever among the students succeeds in killing the teacher, whom they have named "Koro Sensei" (殺せんせー Korosensē, a pun on korosenai (殺せない, unkillable) and sensei (先生, teacher)). However, this has proven to be an almost impossible task, as not only does he have several superpowers at his disposal, including the capacity of moving at Mach 20, but he is also the best teacher they've ever had.