Ahead lies something you hold dear—but to claim it, you must lose something first : The story begins with Sora and his friends going into Castle Oblivion. There, we first see Naminé sketching the castle in sketchbook. Slowly, but surely Sora and his friends began losing their memories as they wanders deeper within the mysterious place hoping to find their lost friends.

As the search continues, fragments of the past seem to start coming back to Sora. He began to remember a blonde girl in his islands. Before Kairi ever came along, it was just himself, her, and Riku. She was a great artist as far as he remembered. When Kairi did come along, she soon left the islands, never hearing from hear again.

Upon reaching the seventh floor, Sora and co. see a girl organization member. No.12, Larxene. She begins to taunt Sora about the girl he just can't seem to remember. Larxene begins to tell him she is being held captive within the castle causing Sora to be enraged. Sora tries to say her name, but it doesn't come back to him. Larxene begins to give him hints until her name is finally remembered.

As the name comes back to him, Larxene strikes Sora causing yellow star-shaped charm to fall to the ground. Then it hits Sora; Naminé was the one who gave that to him. Larxene attempts to smash it, but Sora attacks and yells, telling her to not touch it.

Sora becomes angry at the fact that one of the antagonists keeping her helped him remember her name. She was just too precious to him for that to happen. After Larxene had finished her fight with Sora she soon leaves Sora and his friends.

Sora now has forgotten about his pursuit for Riku and now searches relentlessly in the castle for Naminé. Soon enough though, the gang finds Riku. Riku becomes angryat the fact that Sora is only searching for her, but Sora tells him that he was searching for him too. Riku tells Sora that Naminé is sick of him and that was the whole reason she left the islands. He also tells Sora to just go away and that he'll be the one to protect Naminé. Sora is shocked by what Riku tells him and soon enough the two commence in a fight. After the battle Riku runs off leaving Sora behind calling him out. Now Sora tells himself that he'll save both Riku and Naminé.

Throughout the castle we see many scenes with Naminé drawing and during that time Sora begins to remember more and more about her; not even paying attention to what he is slowly forgetting.

Upon reaching the eleventh floor, Sora & co. come across Twilight Town. The memories rush back once more and he remembers a childhood promise he made with her. One night dring a meteor shower, Sora and Naminé were watching it together. She says "What if a shooting star hits the island?" So Sora tell her "If a shooting star comes this way, I'll hit it right back into outer space!" That was the time when she gave him her good-luck charm. She told him that she had it since she was a baby. Afterwards he told her he would keep her safe no matter what.

After the events of Twilight Town, the group comes across Riku once more. Sora tells Riku that the one controlling him, Vexen, is now gone since they finally defeated him. But Riku disagrees. He is doing this of his own will, of his own promise to Naminé at the beach during the night of the meteor shower. Sora becomes confused, and Riku proves it to him by pulling out the charm that Naminé had given him. Sora tells him that he made that promise with Naminé and pulls out his charm. The two fight once more, and afterwards Riku runs off again.

Even after the whole Riku event of having the same charm, Sora continues on his search for Naminé, to the point of even abandoning his other friends by going on his own. In another room, we see Naminé sitting down on a chair with a sad look on her face. As soon as Marluxia and Larxene leave, she begins to speak to herself...

"Sora... Even if you come for me—what then?"