Sora is an original character created by Tetsuya Nomura, the protagonist of the series and the character that the player directly controls through a majority of the series. Sora's weapon is the Keyblade. Though not the original one chosen to wield the Keyblade, Sora was ultimately chosen over Riku because Sora's heart was stronger, while Riku's heart became vulnerable and temporarily weak. Nomura has stated that Sora's name can be interpreted as "sky"; the Japanese word for sky is sora . Over the course of the games, Sora grows older and matures. Nomura wanted to help illustrate this by having his fighting style in Kingdom Hearts II reflect his maturity; the combat system was completely reworked in the game for this purpose.