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.
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.
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.
While Rei finds Kosuke's ring, the trophy, and a skull at Kazami's office, Kazami disappears after he promises to confess to Sawa's abduction. As a result, Sawa's parents become strictly against her marriage.
Shoko confesses to the murder of her husband, and Rei plays along with her lies. Shoko gets arrested, and Rei breaks up with Sawa. But later, Rei finds an envelope with an enclosed copy of Kosuke's diaries on his desk.