One night, Chiemi Honda and childhood friend Nobuaki Kanazawa receive an email. The sender is the King and the subject of the email is "King Game." The email states that if the recipient does not complete the king's order within 24 hours then they will be punished. Since that first email all of Chiemi's classmates receive an email from the King. At first, students think it's a joke, but perform the orders anyways. Gradually, the orders become worse. Finally, 2 classmates who do not follow the orders are punished. Then classmates start to disappear in sequence. Maria Iwamura stares at one classmate coldly. With Maria Iwamura, Chiema Honda gets closer to uncovering the identity of the King, but tragedy is about to come to Chiemi..

In the distant future, humanity has split into two groups: one that has left Earth to explore the cosmos, and another that remains behind, surviving on the planet.