The player starts the game controlling Roxas, a 15-year-old boy living in Twilight Town. He is on summer vacation with his three best friends, Hayner, Pence, and Olette. As a week goes by, strange things begin to happen. A man named Axel, a member of Organization XIII, becomes upset at Roxas for not remembering him. They fight, and Roxas discovers that he can use a Keyblade. Roxas also meets Naminé and a man named DiZ who was in Riku's side of "Chain of Memories". Naminé tells Roxas she has been changing his memories so he can become "whole" again. Axel tells Roxas they used to be friends and that he must either take Roxas back to the Organization or destroy him. They battle, and Axel disappears. Roxas then finds Sora, and disappears himself. After Roxas disappears, Sora wakes up and becomes a playable character. Donald and Goofy also wake up, and the three of them continue their mission to find Riku. As they search for him, they meet the rest of the members of Organization XIII and learn that they are beings called Nobodies. When a Heartless steals someone's heart, that person also becomes a Heartless, but if their heart is strong, their body becomes a Nobody. Nobodies have no emotions, but want to have hearts again. Xemnas, the leader of Organization XIII, is trying to summon Kingdom Hearts, which he claims will enable the Nobodies to get their hearts back. To summon Kingdom Hearts, Heartless must be killed with a Keyblade, which will release the hearts they hold and let them return to Kingdom Hearts. This is the reason the Organization wanted Sora to join them. It is later revealed that Roxas is Sora's Nobody and was a member of Organization XIII. Roxas was created when Sora briefly lost his heart. Naminé reveals herself to be Kairi's Nobody, who was created when Kairi lost her heart at the beginning of "Kingdom Hearts". Xemnas is the Nobody of a man called Xehanort, who no longer exists. Ansem, the main enemy from the first game, was Xehanort's Heartless. After defeating Xemnas, Sora and his friends return home.