A legal apprentice Rei and his fiancée Sawa are a happy couple. However, there is a big secret that Rei cannot tell anyone--he killed his father 11 years ago. One day, Rei receives an anonymous message indicating someone knows his dark past.

The body of Kosuke, Rei's father, is dug up by someone. Rei becomes very agitated and decides to turn himself into the police but Shoko, Rei's mother, stops him.

Rei and Shoko are informed by the police that Kosuke's car has been discovered. Rei becomes terrified knowing that the person who knows his secret reported the location of the car to the police.

Shoko slips and falls on the stairs at work, but Rei is suspicious of her story. In the meantime, Rei and Sawa plan to go to the fireworks show, but Shoko opposes the idea, worrying that the fireworks may cause Rei to remember the horrible events that took place 11 years ago.

Sawa receives the trophy Rei used to kill Kosuke by mail, and surprisingly Kosuke is the sender. In the meantime, Sawa's brother Akito warns Rei not to involve Sawa in any more trouble.

Someone has replaced the engagement ring Rei bought Sawa with Kosuke's ring. In the meantime, Detective Ichinose is suspicious of Rei and Shoko because they have never seriously tried searching for Kosuke so he begins to re-examine Kosuke's disappearance.