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!!