High school student Sara Chidouin has been experiencing the unsettling feeling of being watched for the past few days. While walking home with her friend Joe Tazuna one night, the pair cross paths with a shadowy figure, prompting them to flee out of fear. Although they manage to make it to Sara's home, they are suddenly abducted and lose consciousness, eventually waking up to discover that they are being forced to participate in a deadly game.

Narrowly escaping the room they were being held in, the two find themselves in a mysterious facility with nine other people who have also been abducted for the twisted game: homemaker Kai Satou, baseball player Q-taro Burgerberg, art student Nao Egokoro, schoolteacher Kazumi Mishima, police officer Keiji Shinogi, singer-songwriter Reko Yabusame, job-hopper Sou Hiyori, elementary school student Gin Ibushi, and middle schooler Kanna Kizuchi. In order to stay alive, the group is forced to work together to solve puzzles and navigate deadly traps. But this is only the beginning of their ordeal, as their captors have something more sadistic in store: vote on who gets to die themselves.