Kingdom Hearts Union χ takes place during the earliest known time period of Kingdom Hearts, in which Keyblade wielders are gathered in a place known as Daybreak Town. Every wielder belongs to a faction known as a Union, each led by a Keyblade Master known as a Foreteller. These Unions initially all share the goal of exterminating the darkness, however, they soon find themselves distrusting one another, which leads to a devastating war. The surviving wielders must figure out what to do next.