Assassination Classroom

Assassination Classroom (暗殺教室) is an ongoing Japanese manga written and illustrated by Yūsei Matsui that has appeared in Shueisha's Weekly Shōnen Jump magazine since July 2012.

A live-action film has been announced for March 2015 and an anime series based on the manga is scheduled to premiere on Fuji TV on January 9, 2015. The manga has also been adapted into a VOMIC and an OVA.

Plot
A strange new teacher is introduced to Class 3-E at Kunugigaoka Junior High School. The teacher is a round-headed, tentacled alien capable of moving at speeds of up to Mach 20 whose color changes depending on his mood. Prior to introducing himself to his new class, he managed to carve out a large chunk of the moon to become a permanent crescent moon. In a year, he plots to destroy the earth, but decides to teach a junior high school class in the meantime for an unknown reason. With this strange creature having effectively taken over the world, the government reluctantly complies with his request on the condition that he does not harm his students.

Affectionately, the students of Class E call him Korosensei, which is pun on the term korosenai (殺せない) and sensei (先生). These same students greet him everyday with assassination attempts in their journey to save the world by eventually murdering their own teacher, and to earn 10 billion yen from the government.

Korosensei
Class 3-E's giant yellow octopus-looking homeroom teacher and the one who destroyed 70 percent of the moon. Korosensei is a near invincible creature with a maximum speed of Mach 20. Despite the fact that he plans to blow up the earth in March of next year, he's still undoubtedly an incredible teacher who cares very much for his students.

Nagisa Shiota
The smallest boy in Class 3-E who possesses an androgynous appearance. Nagisa has light blue hair pulled up into pigtails and ranked 5th best in marksmanship on the boys' side. He's the main perspective character and keeps track of of his homeroom teacher's weaknesses in a small notebook. Despite his lack of notable physical capabilities, Nagisa possesses a natural talent for assassination.

Karma Akabane
A close friend of Nagisa and a major trickster. Karma is an intelligent boy and the top student in Class 3-E as well as one of the top students overall in Kunugigaoka. Unlike the majority of Class E, who were put in there for low grades, Karma was put in there for violence. He's ranked third for marksmanship on the boys' side and out of all his classmates, he's the most enthusiastic about killing his teacher.

Tadaomi Karasuma
An agent from the Japan's Ministry of Defense and Class 3-E's P.E. teacher. Karasuma is a stern yet kind man who was sent to Class 3-E to monitor Korosenei. He possesses super-human abilities and is one of, if not the strongest, human adult to appear in the series. Like Korosensei, he also cares very much for the students in Class E.

Irina Jelavic
A honey trap infiltration assassin and Class 3-E's English teacher. Originally an antagonist who though little of the students in Class E, Irina now cares for them as if they were her little brothers and sisters. Her main abilities lie in her communication and seduction abilities which have allowed her a track record of eleven kills. She has a crush on Karasuma and is affectionately referred to as "Bitch-sensei" by her students.

Setting
The story takes place at Kunugigaoka Junior High School's Class 3-E. A discriminated class filled with trouble students who were expelled from the School's Main Building.

Reception
The manga placed second in male-oriented comics category on the list of "Book of the Year" by Media Factory and manga news magazine Da Vinci. It was number one on the 2014 Kono Manga ga Sugoi! Top 20 Manga for Male Readers survey. It is the only manga that managed to enter Japan's Top 10 Best-selling 2013 and 2014 that were not yet adapted into an anime.

Trivia

 * This is Yusei Matsui's second series in Weekly Shonen Jump, after Demon Detective Neuro Nougami.