Humanity was on the edge of extinction in the year 1939. A strange extraterrestrial species known as the Neuroi initiated an assault of Earth, devouring the world, obliterating countries, and defeating human armies, armed with weapons of destructive strength. The world's powers banded together to combat this apparently unbeatable force. The Striker Unit, a revolutionary gadget capable of combating Neuroi technology, was developed. The Witches, a group of girls outfitted with the Striker Unit, were humanity's final line of defense. They started fighting the Neuroi with their newly improved magical skills and devastating weaponry that no human could handle.