Kingdom Hearts χ Back Cover

In the "age of fairy tales," seven individuals in Daybreak Town protect the world’s light using Keyblades: one Master of Masters and six apprentices. A catastrophic conflict is predicted, with the world on the brink of destruction. To address this, the Master assigns each apprentice a specific role and directs them to create Unions with other Keyblade wielders. Shortly after, the Master of Masters disappears.