In 2015, defense attorney Takayuki Yagami investigates and successfully clears accused worker Shinpei Okubo of a murder charge. However, Okubo is arrested shortly thereafter for allegedly murdering his girlfriend. Guilt-ridden, Yagami resigns from his law firm. Three years later, Yagami has become a private detective in Tokyo's Kamurocho district and accepts investigation requests with his partner, ex-Tojo clan member Masaharu Kaito. A serial killer has been murdering yakuza members in Kamurocho and removing their eyes. Yagami accepts a murder case concerning a Matsugane clan captain, Kyohei Hamura, who is suspected of killing a Kyorei clan member using the same methods. Yagami proves Hamura's innocence, though he suspects that he is working with the killer Yagami dubs the Mole. Hamura orders him to stop investigating the Mole.