on the opinions of fans and the development staff. Another criterion for inclusion was whether the staff felt the characters would fit into the storyline and in the Kingdom Hearts universe. Nomura was hesitant to use characters he did not design because he was unfamiliar with the background work of such characters. For Kingdom Hearts II, he changed his mind after receiving pressure from his staff. Throughout the development of the games, Nomura has often left certain events and connections between characters unexplained until the release of future games. Nomura did this because he feels that games should have room for fans to speculate and use their imagination. He stated that with speculation, even though a game may get old, people can still be happy with it. Main original characters Sora Young Sora is the main protagonist of the Kingdom Hearts series, and the sole playable character of the original game. He is portrayed as a cheerful 14-year-old boy who lives on the Destiny Islands with his two childhood friends, Riku and Kairi. When his world is beset by creatures of darkness known as the Heartless, Sora comes into possession of a weapon of light called the Keyblade, and he embarks on a journey alongside Donald Duck and Goofy to protect other worlds from the Heartless and nobodies and other forces of evil. Nomura has stated that Sora's name can be interpreted as "sky", as the Japanese word for sky is . Riku Young Riku is a childhood friend and rival of Sora who resides with him and Kairi on the world of Destiny Islands. Originally appearing as a non-playable character in the original game, where he is introduced as a 15- year-old boy, he has a playable role in the "Reverse/Rebirth" story mode of Chain of Memories, the multiplayer mode of 358/2 Days, and the core story of Dream Drop Distance. He is also a computer-controlled party member exclusive to the final level of Kingdom Hearts II, and is temporarily playable during a sequence where Sora is incapacitated in the game's final boss battle. Riku is also briefly playable at several points in the "Dark World" in Kingdom Hearts III and is playable a few times in the Re Mind expansion of Kingdom Hearts III. His signature weapon is the "Soul Eater" sword, a manifestation of the darkness in his heart. During the first game, Riku is revealed to