Mahou Shoujo Okaa-San

Chuya Futaba is a young single mother working part time at a supermarket in the heart of Tokyo. She spends most of her days taking care of her son Eito and worrying about piling bills. But when a mysterious woman appears telling her that an evil being wishing to destroy the Earth has marked her son as its host, Chuya must protect her son from not only its underlings, but the heroes hunting for his head. Armed with a crayon and a mother's love for her child, Chuya will fight to free her son!