One of the Princesses of Heart who appeared in Kingdom Hearts, Kingdom Hearts: Chain of Memories and Kingdom Hearts II. She is originally from the Disney animated film "Beauty and the Beast" (1991). For Kingdom Hearts, she spoke using dialogue boxes, but in Kingdom Hearts II her role was greatly expanded and she was thus voiced by her original voice actress, Paige O'Hara.
Kingdom Hearts
Belle's first appearance was a stained-glass likeness of her depicted on top of a yellow-colored pillar in the Awakening world. She was asleep in the artwork, suggesting that she had already been captured by Maleficent at that time.
Belle had been living somewhat happily at the Beast's Castle, becoming closer to the Beast everyday, despite his hideous form and uneven temperament. One day, however, Belle was kidnapped by Maleficent as part of the plot to obtain Kingdom Hearts. The Heartless consumed her world, causing all of its enchanted inhabitants to disappear into darkness. But the Beast managed to survive the destruction of his world, and pursued Belle, using corridors of darkness to reach her at Hollow Bastion.
Maleficent put Belle into an enchanted sleep and placed her in an upstanding glass case alongside the other Princesses of Heart. She then used all of the Princesses hearts to open the Final Keyhole. At the same time, the Beast witnessed a vision of Belle transforming into a Heartless (although this is not what actually occured, as the Princesses lack darkness in their hearts, and cannot become Heartless).
Belle's heart was later restored by the bravery of Sora, and she was released from her enchantment. She seperated from her fellow Princesses and, due to her passion for books, went to Hollow Bastion's library in search of ways to stop the darkness. Happily reunited with the Beast at last, she explained as best she could to Sora what had occured in Hollow Bastion during his brief departure, and then gave him the Divine Rose keychain. When Sora finally sealed Kingdom Hearts, Belle and the Beast returned home together.
Kingdom Hearts: Chain of Memories
The following events were really a corruption of Sora's memories from Kingdom Hearts, and thus they did not actually occur in the Kingdom Hearts reality. Sora, Donald and Goofy entered Sora's memories of Hollow Bastion through Castle Oblivion only to find Belle and the Beast in a heated argument near Hollow Bastion's entrance. The Beast attempted to explain to Belle that he had come from very far to rescue her from Maleficent, but Belle insisted that the Beast leave as she had no interest in talking to him. She eventually retreated to Hollow Bastion's library, leaving the Beast in depressed confusion.
Sora and his friends later found Belle in the library, and attempted to understand her oddly cold attitude towards the Beast. However, before she could explain, Maleficent entered and demanded that Belle call the Beast. When she refused to do so, Maleficent transported herself and Belle to a different area of the castle.
Belle continued to refuse Maleficent's demands, even under the threat of torture. Sora arrived just in time, as did the Beast. Belle continued her increasingly rude attitude towards the Beast upon seeing him, prompting the Beast to pour out his true feelings for her. Maleficent then threatened to steal the Beast's heart, which he had shown to be rich and vulnerable when explaining his love for Belle. As Maleficent attempted to take the Beast's heart, Belle sacrificed herself to save him.
Maleficent later revealed to the Beast, Sora, Donald and Goofy that Belle had been purposefully shunning the Beast in an attempt to prevent herself from exposing her heart for Maleficent to use for dark magic. After Sora defeated Maleficent, Belle was returned to her physical state with her heart intact. She quickly apologized for her actions, which the Beast easily forgave knowing that they were not her true feelings.
Kingdom Hearts II
A year after the events of Kingdom Hearts, Belle and the Beast were attempting to return back to their normal lives at the Beast's Castle. However, the peace was soon disrupted by Organization XIII member Xaldin. Xaldin began playing on the Beast's anger, attempting to enrage him to the point that his heart would be drenched in darkness, thus spawning an extremely powerful Heartless and Nobody variation of the Beast for the Organization to use. In an attempt to keep them safe, the Beast forced the majority of his servants into the castle's dungeon. Belle, not knowing what to do and fearing the Beast's sudden surge of rage, hid in her room in fear. She was overjoyed when Sora, Donald and Goofy happened to drop by.
Once Sora freed the servants from the dungeon and utilized their aid to make the Beast calm down, the Beast realized he had been rude to Belle in his blind rage. Hoping to apologize, he headed off with Sora to find her, only to hear her muffled voice in the castle's ballroom. Belle had taken it upon herself to confront Xaldin on her own, warning him to leave the Beast alone. Xaldin used his influence of the darkness to set a Shadow Stalker on Belle. She managed to evade it, escaping to the ballroom's balcony. After the creature was defeated, the Beast apologized to Belle, who accepted his kind words but reprimanded him for not trusting her.
Sora later returned to find Belle and the Beast in the middle of a date. As the couple began a romantic dance in the ballroom, Xaldin interrupted the celebration, much to Belle's displeasure. She was forced to briefly retreat as Xaldin sent a horde of Nobodies after Sora and the Beast. When the enemies were defeated, Belle returned only to find the Beast in great distress about his enchanted rose. Following him upstairs, she pleaded the Beast to explain what was wrong, but the Beast's frustration simply lead him to order Belle and Sora to leave the castle.
Belle retreated to her room in despair, eventually going out to the balcony to mull things over. When she later spotted the Beast, along with Sora, Goofy and Donald, emerging into the castle courtyard she headed back inside, but on her way spotted the rose sitting near the door. Happily showing off the rose to her companions below, she soon realized the whole thing was a setup as Xaldin grabbed her from behind and flew her to the bridge outside the Beast's Castle. As Xaldin offered the Beast a choice between Belle or the rose, Belle showed Xaldin she was not just a simple village girl. She elbowed the Organization XIII member hard in the stomach and, smiling to herself, ran back to the castle clutching the rose in its bell jar.
Once the Beast and Sora defeated Xaldin, Belle gladly returned the rose to the Beast. He nervously asked her to stay with him in his castle, to which she happily agreed.
At the conclusion of Sora's adventure in Kingdom Hearts II, it was revealed that the Beast had transformed back into Prince Adam, effectively ending the Beauty and the Beast story arc in Kingdom Hearts, although Belle's status as one of the Princesses of Heart may still tie her in to future Kingdom Hearts adventures.
Trivia
Belle's heroic scene in Kingdom Hearts: Chain of Memories took place in a random area of Hollow Bastion, while in Kingdom Hearts: re-Chain of Memories the scene was relocated to Hollow Bastion's entrance hall.