Living peacefully on a faraway planet, the LocoRoco and their friends, the Mui Mui, help grow vegetation and look after nature, making the planet a pleasant place to be, playing and singing the days away. When the Moja Troop comes to the planet to take it over, the LocoRoco do not know how to fight against these invaders from outer space. As such, the player assumes the role of "the planet" that is capable of tilting back and forth, and bouncing the LocoRoco in the air, to defeat the Moja Troop and rescue the LocoRoco. The player will also meet many different characters along the way, some of which are unknown to the player. The player must find out how to interact with these characters, and find out what they know, while determining if they are beneficial or should be avoided as foes. Mui Mui can be found in secret areas within the game.