At the scene of a series of incidents where humans are transforming into demons, surveillance footage captures a culprit who bears an identical appearance to the male protagonist. The female protagonist receives an arrest warrant from the underworld and apprehends the male protagonist, leaving him to await judgment by the Black and White Impermanence. To prove his innocence, the male protagonist devises a scheme to force the female protagonist into investigating the truth behind the cases. As the cases gradually come to light, the two uncover a deeper conspiracy underlying the wave of human demonization, as well as the connection between the culprit and the male protagonist—revealing that everything has been orchestrated by a hidden mastermind.