With a bright and gentle demeanor, Sakura Sakurakouji possesses impressive martial arts skills and an unwavering sense of justice. When she witnesses a group of people being engulfed in blue flames during her bus ride home, Sakura calls the authorities to ensure that the killer is brought to justice. However, much to her surprise, no evidence can be found. Sakura's doubts vanish the next day when she meets the new transfer student, Rei Oogami. He is the very same boy she saw committing the heinous crime. Despite his popularity and endearing nature, Sakura soon discovers that he is a Code Breaker – a person who is essentially nonexistent. Rei possesses mysterious powers and seeks retribution based on the principle of "an eye for an eye". Unwilling to let Rei continue down a path of violence, Sakura attempts to guide him towards a more benevolent way of life. She maintains a close relationship with him in an attempt to redeem him before he causes further harm to others.