Kanazawa Nobuaki has transferred to a high school far from where he used to live. Due to an incident at his old school, Nobuaki is afraid of getting close to his new classmates and keeps himself at a distance, but he starts opening up because of a sports day inter-class relay. Then, a single text message from someone calling themselves the “King” is sent to everyone in class. Nobuaki’s classmates think it's a simple prank, and don't take it seriously–but Nobuaki knows that a death game is about to begin, and struggles to oppose it…

The students of Kamishiro High-School Class 2-A swore revenge on their homeroom teacher, Takao Nanami. Against her, a fake suicide had been concerted, meant to be played out by one of her students, whose actual death would later sink the class into confusion. Who soiled the water with blood? Skinned of its trust, their friendship became an urge to sate each other’s hunger.

A mysterious command arrives from the “King”. The life-threatening “Game” has now begun for the 32 students of the first year's B Class. One day, all of the students in Nobuaki's class received their first message from someone calling themselves the “King”, in which was written a baffling command. That first command was very easy. However, the commands began to escalate until a life-threatening game had begun. Failing to obey the orders leads to death!! Their friendships are being undermined by a bottomless terror!!