Beast's Castle
You arrive at the Beast's Castle under orders from Chirithy to rid the land of the Heartless that plague it. Chirithy encourages you to enter despite your obvious lack of an invitation in order to defeat the shadowy creatures, but despite your best efforts, there appears to be no end in sight of them. You struggle against the enemy's onslaught, when suddenly a ferocious beast appears and singlehandedly defeats all of the Heartless. He seems to be unable to recognize you as a friend rather than a foe, and captures you and throws you into the dungeon without warning.
Chirithy recognizes that the beast has allowed the sadness in his heart to take control and give way to darkness, and that the Heartless are being drawn to the castle because of him. As a Keyblade wielder, it's your duty to defeat them, but you can't do anything while you're trapped behind bars. Thankfully, a young woman named Belle and the castle's enchanted servants set you free. Belle has seen how the Beast has lost his true kindness and reverted back to this selfish nature, but she believes she can talk some sense back to him. Due to your expertise in dealing with the Heartless, she asks you to help them save the Beast.
As you confront the Beast, you realize he is lashing out to protect the enchanted rose, a symbol of the curse placed onto him and his castle and his only measurement of hope to return to human. In his desperation to prevent the Heartless from stealing it, he has allowed the sadness to consume himself, leading him to suspect even his most precious friends of wrongdoing. He has prioritized the rose over all else, but Belle refuses to accept it. She accuses him of causing the monsters to appear and giving up on those who are most important to him. Her harsh words are able to snap him out of his sadness, and give the Beast a newfound determination.
Belle had been there for the Beast at his lowest point, and her belief in him never wavered. He realizes she is his most treasured person, and to thank her for bringing light into his life, the Beast offers her an extraordinary gift; the castle's library, and a special night with just the two of them. Though it seemed like all was well and done in this world, you witness Belle leaving the castle before the night is even done. When you follow her, you discover Beast had let her go in order to save her father, who had been trying to find his way back to the castle and fallen ill. Though he had done so out of love, doing so meant that the Beast had given up his only hope and returned to the abyss of sadness that plagued him.
When Gaston storms to the castle with a horde of Heartless to eliminate the competition for Belle's love, Beast did not even try to fight back. You and the servants do all you can to defend it but are unable to reach through to Beast. Belle returns just before he allows himself to be killed and he retaliates, driving Gaston back. Realizing that she is the source of his strength, Gaston summons a tremendous Heartless to prevent her from reaching the Beast, though it is a failed attempt as you defeat the Heartless and allow Belle to support her friend. With his most important person by his side, the Beast forces Gaston back, ultimately sending him to his death. However, not even he could survive the battle, and Beast passes away from his wounds in Belle's arms.
The pain of losing the Beast allows Belle to finally admit her love for him, thereby breaking the curse placed onto him by the enchantress. The magic that erupts from the curse's lifting spreads over the castle, reviving the Beast and transforming everything back to their original forms. Having returned to his human form, the Beast - Prince Adam, is able to live happily ever after with Belle.
