In 1977, in Yonaki Village, Kazunari Honda and his cousin and girlfriend, Natsuko Honda, lead a quiet life, even though most of the other villagers disapprove of their relationship. However, they will soon face concerns far greater than the townsfolk's opinions when a mysterious black envelope arrives, notifying the villagers that they are to participate in the "King's Game." The rules dictate that the commands must be obeyed by the end of the day and that no one is permitted to quit. While most initially dismiss the envelope's appearance as a joke, they quickly discover that those who fail to follow the orders will die. As more villagers perish, Kazunari and his friends come to understand that they must play the dreadful King's Game, all while suspecting that one of the villagers might be the King.