In 20XX civilization has broken down, and now guns and weapons rule the streets. In the most violent city Yokohama, Milly's husband and daughter were viciously murdered in front of her by 4 guys known as the "Jack Brothers". She barely survived with a near fatal injury, and swore revenge. She learned the art of sword combat from a master swordsman named Juubee, and eventually heads to the abandoned manufacturing plant that the Jack Brothers hang around. Hell's gate has now been opened.