Haruto Higashiyama, a man who became a high school teacher because he wanted to be killed by a high school girl. As a popular teacher, he has been secretly and meticulously devising a "perfect plan only for this" for nine years in order to realize the "ideal way of being killed" while living his daily life. His ideal conditions are two "perfect crime" and "killed with all his might". In a bright and peaceful school, the man's plan progresses quietly and steadily.