Cinderella

One of the Princesses of Heart, her world was destroyed by Maleficent. She was taken and held deep within Hollow Bastion until all seven Princesses were collected. She and the other princesses upgraded Sora's Fire spell to Firaga. She first appeared in Hollow Bastion in Kingdom Hearts.

When Kingdom Hearts was sealed she was returned to her own world.

Kingdom Hearts II
Although she did not appear in the game, Cinderella's name was part of the password that allowed access to the DTD dataspace in Tron's world.

Birth By Sleep
Cinderella is set to appear in the upcoming PSP game Birth by Sleep.