* A media mix project based on an idea by [Itou Kazunori].
Yuu Morisawa is a precocious 10-year-old girl, whose parents run a crepe shop in Creamy ga Oka and who likes Toshio, a boy, three years older than her. One day, Yuu runs into aliens that have trouble with their damaged spaceship. In appreciation for helping them repair the spaceship, the aliens give Yuu a magical wand with one condition; she must keep it secret, otherwise she will lose the special power. She is also given two cats, Posi and Nega, who are to watch over her while she has magical powers. In order to attract Toshio, Yuu decides to transform herself into an attractive 17-year-old girl! Yuu, with the 17-year-old figure, happens to be discovered as an idol singer and makes her debut as [Creamy Mami]. But she never could have imagined that Toshio would start to be attracted to Creamy Mami, and not Yuu herself.
Note: The series pioneered the media mix strategy, with the real idol singer, Takako Oota (Creamy Mami), debuting as an idol singer both in- and outside the story. It was the first of such series in Pierrot's Magical Girls line-up.