Kingdom Hearts II is an action role-playing game, and the primary entry to the series since the 2002 Disney Interactive and Square collaboration. The game's setting is a collection of various levels (referred to in-game as "worlds") that the player progresses through. As in the first game, it II allows the player to travel to locales from various Disney works, along with original worlds specifically created for the series.

One year after the events of Kingdom Hearts: Chain of Memories, Sora, Donald and Goofy awaken in Twilight Town. Bent on the quest to find Riku and King Mickey Mouse, the three begin their journey. However, they soon discover that while they have been asleep, the Heartless are back. Not only that, but new enemies also showed up during their absence. Sora, Donald and Goofy set off on a quest to rid the world of the Heartless once more, uncovering the many secrets that linger about Ansem and the mysterious Organization XIII.