THE iDOLM@STER SP is a series of three Japanese raising simulation video games in THE iDOLM@STER game series. They were released on as Perfect Sun, Missing Moon, and Wandering Star for the PlayStation Portable as a port of THE iDOLM@STER. The gameplay in SP features changes from its predecessor, including an additional promise system which puts more of a focus on communication. The games include three game modes: two single-player and one multiplayer mode for up to three players. The story is told from the perspective of a producer in charge of training 10 prospective pop idols on their way to stardom, and each version of SP features different idols. One reason for dividing SP among three versions when developing the games was to allow players to buy the version which features their favorite idols. Rival idols were introduced into SP because the development team felt that rivals are essential for THE iDOLM@STER, which also serve to deepen the bonds between the player and an idol. Including downloadable content, the game features 54 songs the idols perform: 34 songs in original versions and 20 remixes of those songs, which have been released on several music albums.