The plot centres around Akira Nikaido, a typical slacker enjoying a routine life in high school. That is, until he meets the mysterious Shirogane, a guy who emerges out of nowhere and informs him that they share a destiny. When Akira learns this, he is taken aback and refuses to accept it. Akira's buddy Aya forgets something at school one night and begs Akira to help her find it. He accepts, but he is assaulted by a shadow creature while there. Shirogane persuades him that the equilibrium between the human and shadow worlds has been thrown off, and that Akira must become a "shin"—a creature of the shadow world—in order to help restore it. The animation has shonen-ai themes which are completely absent from the manga.