Assassination Classroom (Japanese: 暗殺教室, Hepburn: Ansatsu Kyōshitsu) is a Japanese science fiction comedy manga series written and illustrated by Yūsei Matsui. The series follows the daily lives of an extremely powerful octopus-like being working as a junior high homeroom teacher, and his students dedicated to the task of assassinating him to prevent Earth from being destroyed. The students are considered “misfits” in their school and are taught in a separate building; the class he teaches is called 3-E. The series was serialized in Shueisha's Weekly Shōnen Jump magazine from July 2012 to March 2016 and compiled into twenty-one tankōbon volumes.
An original video animation (OVA) adaptation by Brain's Base was screened at the Jump Super Anime Tour from October to November 2013. This was followed by an anime television adaptation by Lerche, which aired on Fuji TV from January 2015 to June 2016. A live action film adaptation was released in March 2015, and a sequel, titled Assassination Classroom: Graduation, was released in March 2016.
In North America, the manga has been licensed for English language release by Viz Media. The anime series has been licensed by Funimation. The series was obtained by Madman Entertainment for digital distribution in Australia and New Zealand.
As of February 2016, the Assassination Classroom manga has over 20 million copies in circulation.
Source : Wikipedia, ALPHA CODERS