Gonzo Densetsu no Keiji (2008)

Gonzo was once the best investigator on the Tokyo police force. However, three years ago he quit the homicide division for mysterious reasons and ever since has worked in the equipment division doing paperwork. His life is much less exciting than it used to be, and he seems to prefer it that way. However, Sakuma, his former subordinate, has been baffled by a case involving the murder of a young violinist, and he asks his old supervisor, Gonzo Kuroki (Seiyo Uchino), to re-enter investigation work and help him.