A naked corpse was found that had its penis amputated on a heavy rainy night. As a result of an autopsy by a medical examiner (Naomi Oki), it was determined that the criminal was the same man as the unsolved continuous murder case since last month. Detective Yajima (Masato Furuoya) and Ishigami (Koh Takasugi) immediately start an investigation, but the case goes in a surprising direction.