The series starts with the murder of a 10-year-old girl in 1984. 15 years later, after the case goes unsolved and passes the statute of limitations, a doctor named Goda Ryoji suddenly quits from his hospital and eventually becomes a detective. In 2008, he meets Sachi, a traveling artist in Paris, and shortly after Goda's return to Japan, he becomes involved in the expired murder case when another detective receives an anonymous phone call.

Pegasus Bookstore is going through hard times due to competition from internet bookstores. Kitamura Aki and Nishioka Riko are employees at Pegasus Bookstore. Aki is 23 years old. She has a strong will and freewheeling personality. She places her job and dreams above marriage. Riko is a 40-year-old single woman. She is the vice-manager at the bookstore. She has pride in her work. The two women have completely different personalities.