Erena was an ordinary girl who looked after her sister, Emille, afer her parents died during a space mission. One day, her town was invaded by lustful aliens know as the Zoid. As Emille was assaulted, Erena encountered a creature named Ovi who turned Erena into a magical girl with the power to fight the Zoid. Erena saved her sister and set out to save the world Erena discoved that her mother was alive as a captive of the Zoid. At the same time, Emille was attacked again. Erena saved her mother