Satomi Oka is worried about his final choir competition but is accosted by a shadowy gangster, Kyouji Narita, who demands karaoke sessions with him.

From coworkers to close friends, Konno and Hiasa drift apart. When Hiasa goes missing, Konno must face what he didn’t say in time.

The Mobile Investigative Unit (known as "MIU") of the Tokyo Metropolitan Police Department attempts to solve cases within 24 hours. Detective Kazumi Shima is selected as a new member of MIU. He is intelligent, with excellent observation and communication skills. Yet, he does not trust other people. He is unable to find a partner in MIU and is ordered to partner with Police Officer Ai Ibuki, who works at a police substation. Ibuki applied for MIU, but he failed. He is in excellent physical condition, but he lacks knowledge and experience as a detective. Shima learns about Ibuki's background and he becomes more nervous. Finally, Shima has his first meeting with Ibuki.