Kingdom Hearts χ Back Cover
Japanese title: キングダム ハーツ キー バックカバー
Type: OVA
Episodes: 1
Source: Game
Genres: Action, Fantasy, Mystery
Producers: Square Enix
Duration: 1 hr 2 min
Rating: PG-13 - Teens 13 or older

Long ago, in the "age of fairy tales," the world's light is protected by seven individuals who reside in Daybreak Town and wield unique weapons called "Keyblades": the Master of Masters and his six apprentices. A devastating conflict has been foreseen, and the world's end is imminent. In order to heal it, the Master of Masters gives his disciples unique roles and instructs them to form Unions comprised of other Keyblade wielders. Soon afterwards, the Master vanishes.

(Source: KH Wikia)