Kimura is one of the relatively proactive students when it comes to assassination and aims to claim the 10 billion yen reward. It is stated that both of his parents are police officers, and they have a high sense of justice, thus they named him "Justice". Even if he doesn't like the name and asks them to change it. He was constantly being teased about his first name being “Justice,” and his concentration dropped. As a result, his grades suffered and he was sent to Class E.