Misao Amano

An evil magical girl, Pixy Misa is the rival and dramatic foil of the series' protagonist, magical girl Pretty Sammy. She is the alter ego of Misao Amano, who is, ironically, the best friend of Sasami, Pretty Sammy's secret identity.

Throughout most of the series, Misao remains unaware of her activities as Pixy Misa.

(Source: Wikipedia)