Assassination Classroom is a Japanese comic science fiction manga series written and illustrated by Yusei Matsui. The series was serialized on Shueisha's Weekly Shonen Jump magazine from July 2012 to March 2016 and is licensed in English by Viz Media. The series follows the daily lives of an extremely powerful octopus-like 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 E-3. The students call him KORO-SENSEI which means unkillable teacher in Japanese. As of July 2016, twenty-one tankobon volumes have been released in Japan with a circulation of 20 million copies.