Chain: The Lost Footprints

Takeshi Shinonome is a private detective. One day, he meets a girl named Ayumu out in the rain. Ayumu's sister, Marie, and Takeshi went to the same high school. She asks him to investigate rumors concerning her husband. Takeshi finds evidence that her husband is having an affair with Ako Sonomura.

Later, Ayumu's father asks Takeshi to investigate her private life. He is a well known politician and is afraid of having a scandal during the upcoming general election.