Tokyo Satsujin Gakuen

Overview

Ayato, a boy who spent his childhood in a foreign terrorist organization, is troubled by the horror of his own past which made him question his own self-worth. But then he is recuited to join a "murder school." Now he fights against the evils of the world with the motto, "There are lives that can be saved by killing!" (Source: Young Champion, translated)

Source: AniList