Whilst Professor Utonium and his son assistant Ken were studying the unknown substance Chemical X, a rice cake accidentally fall into it. A violent chemical reaction occurs, transforming Chemical X into a whole new substance, Chemical Z.That same day, a huge iceberg suddenly appeared off the coast of Tokyo City and Ken fires a Chemical Z ray-beam at the iceberg. The Chemical Z beam changes into white and black lights which are released into Tokyo City. Ordinary first-year junior high girls Akatsutsumi Momoko, Gotokuji Miyako, and Matsubara Kaoru are bathed in white lights and their normal lives are disrupted.Thus, the Powerpuff Girls Z are born!Source: AnimeNFO