Mizuno Asumi is a doctor who has just started to work in an university hospital. She seems a bit unsociable but she has her own secret. Fifteen years ago in this very hospital, her father died. Asumi's life goal is to take revenge on people who caused her father's death. As she investigates the hospital's staff connected to the accident back then, she uncovers that the truth about her father's death isn't so simple and there are many people who are responsible.