Upon awakening, Shai, a will-o-wisp spirit found himself with little memories of who he was or where he came from. However, a strange detective by the name of Hajimari Kami, who seems to know a lot more about Shai than he cares to lead on, takes the aloof spirit and guides him through the world of gods, demons, and yokai. As more dark cases appear in front of the two, Shai begins to piece together his memories and just exactly who he used to be... and just how sinister his world really is...