One day in late 1999, a supernova explodes in the Auriga constellation. Interstellar dust had shielded this star over the long passage of time, leaving it undiscovered by humanity. The eruption of this supernova nearly makes humanity extinct. Humanity enters a new era on this day: the supernova era. Due to Earth’s proximity to the supernova, radiation sickness becomes widespread, and people begin dying on a massive scale. However, people also discover that children—especially those under twelve years of age—exhibit little to no symptoms of radiation illness. Eventually it becomes known that this phenomenon is connected to the self-repairing nature of genes, an ability that deteriorates with age. According to the most optimistic predictions, everyone on Earth above thirteen years of age will gradually die out over the next ten to twelve months.

Thus, in a massive yearlong endeavor known as the “Great Education,” the entire planet’s adult population strives to impart their lives’ worth of knowledge and experience to these young, inexperienced children.

One year later. Only children remain on Earth. Society has been utterly transformed.

In a world populated only by children, war becomes a game, weapons become toys, and the value of life vanishes from view. When this generation of children views war as a game, they forget that there are no restarts in war. In the game of war, everyone has only one life.