Kingdom Hearts RE: Chain of Memories was developed by Square Enix for the PlayStation 2. It is a rerelease of the original Chain of Memories for the Nintendo DS and the game falls between Kingdom Hearts and Kingdom Hearts II and explains why Sora has lost his memory. It makes use of a card system for combat where you must collect cards to make actions.

Kingdom Hearts II is a role-playing game developed by Square Enix and released on PlayStation 2, PlayStation 3.

Kingdom Hearts is a game that follows the story of Sora, the Keyblade Master who has the power to open the doors between worlds. His friends Kairi and Riku go missing and Sora sets out to find them across the various worlds. He is joined by a variety of Disney characters when exploring their worlds including his constant companions Donald Duck and Goofy.