"My first love, murdered..." In January of 1984, a girl in the 4th grade is abducted on the way from school and killed.
The main character, Ryoji is tormented by the mental anguish of not being able to rescue his first love, Sachie. But with Sachie's mysterious death, unsolved for 25 years and past the statute of limitations, Ryoji realizes his true calling. Armed with evidence of her murder that only he knows about, Ryoji ends his career as a doctor and becomes a police detective, in the hopes of finally solving the case.