In a dystopian future, the Japanese government has created a ruthless game to control the rebellious youth population. This game, decreed by the BR Act, selects a junior high school class and sends them to an isolated island for a deadly competition. The students are forced to fight to the death until only one survivor remains. Each student is fitted with an explosive collar and given a random weapon as they scatter across the island, grappling with the shock of the situation and the necessity to kill their classmates in order to survive.

As the game commences, alliances form and friendships are tested under the extreme pressure of the survival challenge. The students' morality, will to live, and the strength of their bonds are pushed to the limit amidst the chaos. Meanwhile, as the game's administrators monitor the players, the teenagers must navigate both the physical dangers of the island and the psychological terror of betrayal, uncertainty, and looming death that hangs over every decision they make.