The idea for Devilman Lady came about when Go Nagai wondered what the future of mankind would be like if the person that became Devilman had been a woman. The manga started in 1997 and made its way onto television in 1998. The television show differs slightly from the manga. Jun is a shy fashion model instead of a school teacher. Despite how the story may sound, Devilman Lady is completely original and not a rehash of Devilman.

Jun Fudo is a teacher who raises her younger brother, Hikaru, while their father is away in the United States. Jun is asked to accompany a group of students an on outdoor trip and she begins experiencing unusual nightmares. To make matters worse, in a nearby chalet are a group of martial artists who take too much of an interest in Jun and her female students. However, these are no ordinary martial artists, but in actuality, they are demons. After reverting back to their true form, they break into the nearby chalet to rape the girls. Jun is caught by the demons and they proceed to violate her.

Feeling her soul being ripped apart, Jun undergoes a terrifying transformation into a demon-woman hybrid. With her newfound strength, she kills the attacking force of demons and gathers the surviving girls to protect them. A woman named Ran Asuka shows up and claims that she awakened the sleeping beast within Jun.

Jun is understandably confused about what is going on and the sudden appearance of her father (who was supposedly in the states) complicate matters for her. According to Professor Fudo, a strange phenomenon occured in shantytowns a couple years ago known as the "Devil Beast Syndrome". Some inhabitants would tranform into demons and rape women before eating them. The "Devil Beasts" do not retain the memories nor intelligence of their previous lives, but gain enhanced strength.

Is there some sort of supernatural explanation for all of this? No. The professor explains that this change that is occuring in people is the next stage in evolution for mankind. Professor Fudo theorized that this was Nature's way of dealing with mankind's overpopulation. A few people were genetically engineered to retain their conscience should the "Devil Beast Syndrome" occur in them. Jun was one such experiment. With Devilman Lady fighting for humanity, there may be enough time to prevent the creation of further devil beasts.