In 2005, a sophomore student named Igarashi Mahane took a private train to Soukyo City. She disappeared after alighting at a station named "Kisaragi". Five years later, her lover, Yokoyama Shizuno, began investigating the case and strange stories started to unfold one after another.

Five years ago, sophomore student Maha Igarashi took a late-night train to Soukyo City to attend a social flash mob event organized by an occult forum. She disappeared midway after getting off at a station called Kisaragi, and the station itself vanished thereafter. Maha's boyfriend, Shizuno Yokoyama, never stopped searching for her. He opened a detective agency in his hometown, specializing in peculiar requests, all in pursuit of clues to find Maha. As his investigation deepens, he finds himself increasingly entangled in the mist of mysteries...