Charcters

Further information: Characters of Kingdom Hearts

The main protagonists, from left to right: Riku, Kairi, Sora, Donald, and Goofy

Because Kingdom Hearts was a collaboration between Disney and Square, it features a mixture of familiar Disney and Square characters, as well as several new characters created and designed by Tetsuya Nomura.^[23] The primary protagonist of the game is Sora, a 14-year old boy who is chosen to wield the Keyblade, a sword-like weapon for battling darkness. The game also features two of his friends, Riku and Kairi. For most of the game, Sora is joined by Donald Duck and Goofy. Donald, the court wizard, and Goofy, captain of the royal guard,^[24] were sent from Disney Castle to find the Keyblade.^[25] The three join forces to search for King Mickey Mouse, Kairi, and Riku. The primary antagonist is Ansem, who is seeking to find power and knowledge by using dark beings called the Heartless. The Heartless, hearts corrupted by darkness, serve as most of the enemies encountered in the game and come in a variety of shapes and sizes.

As a game meant to explore the fictional universes of various Disney films, over one hundred Disney characters are featured in various capacities.^[26] While many serve as major characters in the story, others appear in cameo roles, such as the One Hundred and One Dalmatians playing a part in a side-quest. Most worlds also feature a Disney villain whom the player must defeat. The player can summon various Disney characters to fight alongside Sora in battle, causing Donald and Goofy to withdraw from the battlefield for the duration of the summon. Available summoned characters include the Genie from Aladdin, Tinkerbell from Peter Pan, and Simba from The Lion King, among others.^[15]

Square also incorporated several characters from the Final Fantasy series into the game, though the characters were slightly altered to fit the game's back-story. On Destiny Islands, the player meets younger versions of Tidus and Wakka from Final Fantasy X and Selphie from Final Fantasy VIII. In Traverse Town, the player encounters Squall Leonhart (known in the game as "Leon") from Final Fantasy VIII as well as Aerith, Cid, and Yuffie from Final Fantasy VII.^[15] Rikku from Final Fantasy X and Irvine from Final Fantasy VIII were both originally set to make cameo appearances, but were replaced by Yuffie and Wakka respectively.^[27][28] Cloud and Sephiroth, both from Final Fantasy VII, make appearances in Olympus Coliseum, where the player can fight them in tournaments.^[15] The emphasis on characters from later Final Fantasy installments stems from Nomura's hesitation to use characters he did not design.^[29]

The game also uses other Final Fantasy icons. Moogles appear to provide item synthesis.^[14] Several weapons, such as "Lionheart" and "Save the Queen", share names with other weapons from throughout the Final Fantasy series. Early in the game, Riku suggests the name "Highwind" for the raft that he, Sora, and Kairi build, a reference to the airship of Final Fantasy VII. The magic-naming system in Kingdom Hearts (i.e. Fire, Fira, Firaga, etc.) is identical to Final Fantasy magic. The names of various spells are also the names of Gummi blocks, and various summons, weapons, bosses, and monsters are the names of Gummi Ship blueprints.