Yū Morisawa is an ordinary 10-year-old girl, until she sees a spaceship floating in the sky. Carried into the ship, she helps Pino Pino find the Feather Star. In thanks for her assistance he grants her a magical wand, which allows her to transform into a 16-year-old girl, for one year. She is also given two cats from Feather Star, Posi and Nega, who are to watch over her while she has magical powers. While wandering around the city as a teenager, she accidentally ends up on TV and asked to sing, which the magic enables her to do remarkably well. Using the alias of Creamy Mami, she becomes an overnight success, and is soon sought to begin a professional career as an idol under Parthenon Productions. Along the way, she also meets past residents of Feather Star and supernatural beings. In addition, she must fight against Snake Joe, a shady character of the rival LP Productions, who is always trying to steal her away and Megumi-chan, another one of Parthenon Productions’ top stars.