The Tokyo Metropolitan Police Department's First Personnel Division is an elite group responsible for inspection work to uncover misconduct among the more than 40,000 personnel who work for the police force. It is said that just being the subject of an inspection can end a police officer's career. Feared as police of the police, inspectors like Sara Masaki have a lonely role. Two years on, Sara comes face to face with a conspiracy that will rock the entire police organization.—Jdrama Weblog

Masaki Sara (Masahiro Matsuoka) is a detective of the Investigation Team 1 at Tokyo Metropolitan Police Department. His colleague, Detective Kota Sato, dies during an investigation of a murder case. Afterwards, Masaki Sara is transferred to the Personnel Department 1 of the Inspection Division. He still suffers from the death of his colleague Kota Sato. The other workers around Masaki Sara are hostile to him. One day, a letter reaches the personnel department. The letter claims that Detective Nako Minaguchi leaks secret information. Detective Nako Minaguchi used to work with Masaki Sara in the Investigation Team 1. Masaki Sara begins to investigate the claim in the letter. His investigation leads him to the unsolved case of the death of his colleague Kota Sato.—AsianWiki