Kotaro is a 7-year old boy. He lives with his Mom, and his raccoon robot Pon, in a spaceship shaped like a merry-go-round. One day, he somehow becomes separated from his mom... He ends up heading for the Chocolate Star with his companion Pon, but over there also awaited them an event so big that it would shake the whole star and its inhabitants. Once he gets there he meets Wave; they become friends and start a wonderful adventure.