Yoru no Yatterman

When ten-year-old Leopard's mother gets sick, Leopard tries to get medicine from the prosperous Yatter Kingdom—only to be shot at by the supposedly heroic Yatterman. As she grieves over her mother's death, she discovers her legacy: Her ancestors were the age old enemies of the Yatterman and the villains of countless stories. But if the Yatterman are actually the evil ones, Leopard decides, then perhaps the stories were wrong and her ancestors were the heroes. Thus, Leopard sets off with her two companions—vowing to teach the Yatterman the error of their ways by giving them the forehead flicking they so richly deserve.