Based on the American cartoon “The Powerpuff Girls,” the series follows Professor Utonium and his son Ken as they experiment with the mysterious Chemical X. When a mochi cake accidentally falls into the formula, it transforms into Chemical Z. Ken directs a beam of Chemical Z at a glacier in Tokyo Bay, releasing a burst of black and white lights. The black light turns its targets into monsters, most notably transforming a zoo monkey into the villain Mojo Jojo, while the white light falls on three ordinary girls, Momoko, Miyako, and Kaoru. The girls gain the power to transform into superheroes, becoming the Powerpuff Girls Z.