"Demons." Ageless, immortal beings living in the shadows of the mortal realm. The way to gain immortality is to kill a "Demon"; the price is to take on their role. A man who killed his Demon lover; a Demon who commits suicide over and over without someone to kill her; a girl who interacts with Demons.... The curtain rises on a life-and-death stakes game of musical chairs between Demons and mortal humans.
Kazuhiro Oyamada is a college student suffering from insomnia, causing his health to suffer. Kazuhiro decides to use his summer break to go back to his hometown to recuperate. When he arrives, he can't find his grandparents. Feeling something's off, he asks his parents about them, but they react suspiciously. That's when Kazuhiro discovers the "truth" of this strange mystery... This highly popular suspense-thriller finally has its comic adaptation!!