Mizuka Mizutori is a supporting character in the anime and manga series Bad Girl, created by Nikumaru. She is a first-year student at Fujigasaki Private High School and the younger sister of Atori Mizutori, who is widely admired as the school’s disciplinary committee chairman and a campus idol. Mizuka shares Yuu Yuutani’s intense admiration for Atori, but her devotion goes to an extreme degree, manifesting as a pronounced sister complex. She frequently stalks Atori and obsessively takes photographs of her, a hobby that inadvertently hones her photography skills to an impressive level. Mizuka’s motivations are driven entirely by her infatuation with her older sister; she seeks to be close to Atori and document her every moment. Her role in the story is primarily as a source of comic relief and as a secondary figure whose antics create additional complications for the main characters, particularly Yuu, as both compete for Atori’s attention. Mizuka does not undergo major character development over the course of the series, remaining consistently single-minded in her pursuit of Atori. Her notable abilities include her determination and the practical photographic talent she develops through her stalking. Physically, Mizuka is a teenage girl with multicolored or gray hair styled in twintails, yellow eyes, a height of 149.5 centimeters, and a weight of 43 kilograms. She is typically seen wearing the Fujigasaki school uniform with a vest and tights. Her birthday is January 11.