Satoru's truck-driver father caused a drowsy-driving accident that killed a family of three. His father went to prison, while Satoru and his mother moved repeatedly as if fleeing their past. Fifteen years later, Satoru reluctantly hints at what happened to his mother after he returned from school one day, but cannot bear to finish the story. Despite feeling uneasy during wealthy Iori Takakura's relentless interview, he accepts a mysterious job after being offered exceptionally generous terms—and steps into something far darker.