Because Kingdom Hearts was a collaboration between Disney and Squaresoft, it features a mixture of characters derived from both companies, as well as additional characters created solely for this game. The primary protagonist of the game is Sora. The game also features two of his friends, Kairi and Riku. For most of the game, Sora is joined by Donald Duck and Goofy. Donald, the court wizard, and Goofy, captain of the royal guard, were sent from Disney Castle to find the Keyblade. 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, there are over 100 Disney characters. While many serve as major characters in the story, others appear in cameo roles, such as the One Hundred and One Dalmatians puppies who play 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.
Sora[edit]
The Hero of the Keyblade and the main character of the Kingdom Hearts series. He is 14 years old and lives on the Destiny Islands. He grew up with Riku and has known Kairi for a long time. After the door to Destiny Islands is opened, Sora gains the Keyblade and is cast away to Traverse Town, a mysterious world where refugees of destroyed worlds are sent.
He meets with Donald and Goofy, who have been sent by King Mickey Mouse of Disney Castle to stick by the Keyblade wielder and search for the cause of the darkness in the worlds. He now searches frantically for Riku and Kairi, as well as the source of all darkness.
Sora's Keyblade can be altered if equipped with the any different key chain at the end of it. These Keychains are often given at the end of each boss battle or can be found as a helpful item in random worlds. Either way…each Keychain has different status abilities and strength vs weakness. *There is, as with "all" Final Fantasy games, a secret "Ulitma" weapon that can be found for each main character.
Sora also bears a slight resemblance to Mickey Mouse's classic look. Aside from his spiky hair, white vest, and chain necklace, Sora wears bright red rounded overalls and large yellow shoes.
Riku[edit]
Riku is Sora and Kairi's best friend and is 15 years old. Originally living on the Destiny Islands, he grew up with Sora and has known Kairi for a long time. His desire to escape from the monotony of secluded life causes him to accept the darkness swallowing the island with the belief that it would let him escape the island and explore new worlds. He was originally intended to receive the Keyblade, but his surrender to the Heartless made Sora obtain it instead. Once free of the island, he meets Maleficent, the Wicked Fairy who uses the darkness to her own ends. She attempts to recruit him in her dark cadare but does not truly gain his trust until he grows jealous at Sora's new friends, Donald and Goofy.
Feeling abandoned by Sora, he searches for Kairi alone and will do anything - even giving up all his heart to darkness - to save her.
Riku's weapon, the Soul Eater, is a demon wing-shaped blade which allows him to perform quick and accurate moves. He later gains the ability to forge his muscles with darkness, leaving only his face "human-looking".
Kairi[edit]
Kairi is Sora and Riku's old friend and possible love interest. She is 14 years old. She was born in Hollow Bastion and lived there until she was sent to Destiny Islands by the wicked King Ansem as an experiment following the myth that a Princess's heart is drawn to the Keyblade Hero. She has lived with Sora and Riku for a long time and it is unknown if she shares the feelings they have for her.
She loses her heart following the Door to Destiny Islands being opened, and both Sora and Riku are willing to do anything to find her.
Donald Duck[edit]
King Mickey's Royal Wizard. He plays the role of the black and white Mage (as are in most Final Fantasy Game) and will perform any magic spell that Sora can learn. He is naturally hot tempered and has a heavy quacking accent (yet everyone can understand him). His weapons include staffs of many shape and status abilities…some are even references from Final Fantasy Games. His side ability is to change and alter the looks and appearances of the group depending on which world they decide to visit. For example…he will change Sora into a merman; Goofy into a turtle; and himself into a duck with squid tentacles if entering the "Little Mermaid's" world. Their costumes will also change into spooky figures if entered in "Halloween Town".
Goofy[edit]
King Mickey's Royal Knight and Leader of his Army. This laid-back and clumsy Captain prefers to avoid fighting if can be helped. With such a peaceful place such as Mickey's Kingdom…who needs wars? But when there's danger afoot…Goofy will (if not hesitantly or clumsily) charge into battle to aid his friends. He plays the role as the physical fighter type in the Final Fantasy Genre (meaning he can't learn magic). His "battle-moves" are creative…yet humorous to watch sometimes as he performs clumsy fighting skills that are "surprisingly" effective. His weapon is the Shield which he uses as a method of Charging into enemies "head-on". His Shield comes in various styles…some of which range from small (for more offense) to large (for more defense).
Ansem[edit]
The Main Villain of the first Game. Believed to once be a great researcher of the Heartless before he turned his life to Darkness. His Journals are scattered across the worlds. Piecing them all together reveals a different side of Ansem…is he really the bad guy?
Either way you will face in a final showdown. Be warned…he will be tough if you’re not leveled up.
His main striking features are a royal suit…long silver hair…and a wicked stare. He is followed by a vile looking shadow that serves as his weapon, shield, and bodyguard.
The Heartless[edit]
Strange and mysterious creatures that feed on the darkness in people's hearts. These creatures will attack Sora and range in different shapes…usually dark colors…and have unique abilities (usually accustomed to the area they come from). They seem to resemble the shapes of people or animals which suggests they take the form of whatever dark origins they absorb.
Not much is clear about the origins of the Heartless (at least not in Kingdom Hearts 1). But it is possible that they aren't "purposely-evil" creatures…after-all…they survive on the darkness from "others".
In later parts of the game Sora turns into a Heartless, but somehow does not succumb to its dark habit. He then ventures out to stumble upon Kairi, only to have her inner light restore Sora back to his normal self. This suggests that a heartless may not be "intentionally" evil.
As a special bonus, you can watch a video of the trailer for Kingdom Hearts 2. The Heartless portrayed there have similar basic styles as basic heartless, but look more menacing and "human" like.