Kairi

Kairi is a major character in the Kingdom Hearts series and good friends with Riku and Sora.

Personality
Kairi is caring, kindhearted and not afraid to speak out her mind. However, she is determined and courageous when someone she cares about is in danger, often risking her own safety to help that person. She's also become slightly more withdrawn because of Sora's absence, has obtained wisdom usually beyond someone of her age. She's not as brash and bold as she was in the first game, but she's still pretty sociable. She also makes friends easily, quickly befriending Hayner, Pence, and Olette in Twilight Town. She's usually always very cheerful and upbeat and seems to be bit of a tomboy as well. In contrast to Sora and Riku, who were both bothered by not knowing about Kairi's hometown, she took it in stride and was able to look at the positives about living in the Destiny Islands. She is loyal and headstrong, as well as stubborn to a point though.

Kingdom Hearts: Tears of Destiny
In Tears of Destiny, Kairi is a major character. A strange wind blows through Destiny Islands and she, Sora, and Riku are transported to the world of Crystal Isles. She is separated from Sora and Riku, and finds a large crystal palace and knocks, hoping for help. To her horror, the door is opened by a Heartless. She is captured and thrown in the dungeon of the palace.

Later, Roxas returns to Crystal Isles, and enters the palace. He defeats the Heartless who had captured Kairi, and frees her. She then joins Roxas's party.

Later, Maleficent is bargaining with Hades for Sora's soul. It is revealed she had sent the Heartless after Sora to turn him into a Heartless, but it had killed him instead. Roxas and Kairi then come to the Underworld, and Sora's soul is liberated. His soul, having nowhere to go as his body is being inhabited by Roxas, possess Kairi's body. Both Sora's and Kairi's conciousnesses are in her body, though she is in control of it still. Roxas and Kairi/Sora then continue the quest to defeat Organization XIII. At the end of the game, after Roxas has become whole, he goes back to his own body. Him and Kairi then return to Destiny Islands, believing Riku to be dead.