Kurosaki Kana has been assigned to investigate the serial rapist and murderer X. However, there is little information about X, not even his name, nor any details about him, and there is no decent photo of his face. Kana's father, Goro, a former special agent, also worked hard to investigate X, but was killed in the line of duty before he could achieve his goal. Kana visits Kagami Eiji, a former subordinate of her father and the man who was closest to X, to ask for his cooperation in the investigation. However, Kagami Eiji is none other than X. Kagami becomes interested in Kana, and uses drugs to knock her unconscious...