Mikkoku wa Utau (2021)

Sara Masaki is a detective of Investigation Team 1 at the Tokyo Metropolitan Police Department. His colleague, Detective Saito Kota, dies during an investigation of a murder case. Afterward, Masaki is transferred to the Personnel Department 1 of the Inspection Division. He still suffers from the death of his colleague. The other workers around Masaki are hostile to him. One day, a letter reaches the personnel department. The letter claims that Detective