The youngest and newest member of the Organization, Roxas, the "Key of Destiny", is "born" when Sora becomes a Heartless in Kingdom Hearts. His name is an anagram of "Sora" with an "x" added. Jesse McCartney voices him in the English version of Kingdom Hearts II and Koki Uchiyama in the Japanese version.
Roxas's first appearance is in the Special Secret Movie "Another side, Another story…" that is seen if the player accomplishes certain tasks in Kingdom Hearts; he was the first Organization member to be revealed. He later appears in an additional video, "Another Side, Another Story [deep dive]", for. When pre-release screenshots and video showed this character without an Organization coat, he was featured prominently, emphasizing his importance to the future game's plot.
During Roxas's time in the Organization, he and Axel became friends, but because Roxas had none of Sora's memories, due to Sora's short time as a Heartless, and thus did not know why he had the Keyblade, Roxas left to find answers.
Riku, to help Sora regain his memories and awaken, confronted Roxas in the World that Never Was. Roxas was victorious in the first encounter; after Riku used the power of darkness, Roxas was defeated. Riku took him to DiZ who placed Roxas in a virtual Twilight Town created within Sora's memories without any memory of the Organization and with a fabricated identity to throw off his pursuers. While Naminé restores Sora's memories as DiZ wishes, Roxas is affected by seeing his other self's memories in dreams. Roxas lived an apparently normal life in the simulated Twilight Town until Axel infiltrated the town to save him.
Despite Axel's attempts to stop him and gaining back his memories of the Organization, Roxas merges with Sora in the beginning of the game. Roxas appears two more times near the end of the game in the World That Never Was. The first is a battle with Sora, with Roxas's Samurai Nobodies holding off Goofy and Donald. The fight, where Roxas uses his Keyblades and the power of light, is never fully explained and is left open for interpretation. Roxas appears once again with Naminé before Kairi enters the corridor of darkness back to Destiny Islands. He and Naminé imply that they will not fade but live on within Sora and Kairi as a part of them and as individuals, as seen in the ending cinematic when they smile at each other through their other selves.