Sora is walking down a long, endless road, along with his friends, Donald and Goofy, later that night, Sora woke up, and came to a crossroads. As he gazed as the sky, he begin to think of his lost friends, Riku and Kairi. Suddenly, a mysterious man appeared, "Ahead lies something you need, but to claim it you must lose something dear." The man said, and then vanished, with only one way left, which leads to a mysterious place Sora will never forget in his heart, Castle Oblivion. What danger awaits Sora and his friends, or more importantly, what will he forget?