"Kingdom Hearts Birth by Sleep" is the sixth game of the series for PlayStation Portable. It was released in Japan on January 9, 2010, and in North America on September 7, 2010. The game is set ten years before Sora begins his journey. It follows a shared path between Terra, Ventus and Aqua, the apprentices of Eraqus and Xehanort. They set out to stop Vanitas, the creator of Unversed. "Kingdom Hearts Birth by Sleep Final Mix" is a reissue of the game was released only in Japan on January 20, 2011. It has content from the English version and new features, such as a playable Secret Episode and a hint at a possible "Kingdom Hearts Birth by Sleep -Volume Two-