Fifteen years ago, tragedy struck a small town when a young elementary school girl Emili (Hazuki Kimura) was abducted and killed by a stranger. Four girls who had been playing with Emili at the time were the first to discover her body. The abductor is never found and the crime goes unsolved. Crazed with grief, Emili’s mother Asako (Kyoko Koizumi) condemns the four girls, none of whom can remember the abductor’s face. She tells them, “Do whatever you have to do to find the killer. Otherwise, you can pay a penance that I approve.” Deeply affected by Asako’s condemnation, the four girls become adults burdened with the curse of “penance,” which eventually triggers a chain of tragic events.