|Published on||1997 - 2000|
The story follows Jun Fudo, a school teacher in her early 20s living with her younger brother Hikaru in Japan, whilst their father works away in America for a mysterious organization called the H.A. One day, Jun takes her school's tennis club up for a school trip in the mountains. Unfortunately, once they arrive they are attacked by a group of Devil Beasts who either kill or rape the students. However, a mysterious blonde woman named Lan Asuka psychically contacts her telling her to transform. Under attack, Jun does, killing the Devil Beasts in a frenzy.
Afterwards, Lan and several H.A. Troopers burst in and rescue the survivors while Lan explains to Jun what has happened. The H.A. was created to combat the threat of the feral Devil Beasts, an evolutionary offshoot of humanity. Jun however, is a special case, retaining her human will and Devil Beast-like body, a Devilman. Placed under Lan's supervision, Jun is tasked at capturing or killing the Devil Beasts under the code name "Devilman Lady".
Jun continues to fight the Devil Beasts for the H.A. including a co-worker of Jun's named Mr. Okawa, a student named Mita, a pop idol named Nami Kayami and her mother, an entire village of vampiric Devil Beasts, and her past rival Aoi Kurosaki.
Jun continues to fight, however she does start to doubt whether what she was doing was right or not, especially when a Devil Beast turns out to be a young girl named Akemi who is then killed in front of her eyes. During the battle she meets with Seiji Hayami who becomes a friend of Jun's and helps her on some missions.
At one point, Jun's infiltration job into a cult posing as an embassy of a small country results in her being sent to to Hell. There, she meets Akira Fudo, a young man with a Devilman form very similar to hers who had been trapped in Hell. His exploits have been made into a media series in Jun's reality with Jun's title actually coming from him. Some of Akira's old foes including Jinmen, Sirene, Kaim and Zennon, as well as many new threats such as Vlava, the Cerberus, Geryon and Medusa are also present. Jun and Akira travel through Hell, slowly falling in love and even have sex. After battling countless foes they finally find the way to Jun's world. While Jun leaves, Akira is forced to stay behind without a body. Jun finds herself having been teleported to a time several months before being sent to Hell and slowly begins to lose her memories of her exploits there.
Jun resumes hunting down and capturing/killing rogue Devil Beasts, at the same time several new Devilmen are employed into the H.A. including Mitsiru (A.K.A Devilman Kids) and a surprising return from Aoi Kurosaki now known as Devilman Noir. A new threat emerges in the form of the Cult of Dante led by the mysterious Judah Hiroka. They employ the equally strange Ryo Utsugi (a.k.a. Dante) to travel to Hell and reawaken the great demon lord. Dante finds the frozen body of the demon lord with his body devoured and fused to free the Demon Lord. This releases the entirety of the depths of Hell into the world (including demons, Devilman, and human alike), resulting in worldwide carnage.
Eventually it is revealed that Lan was actually born a male and is actually Jun's half sibling. Later, Psycho Jenny reveals that Jun and Lan were actually defused aspects of Satan, who had gone into hiding after escaping the time loop that God had placed him/her in and the Archangel Michael went to hunt for him/her. It is also revealed that Michael had single-handedly set up the H.A. to tackle with any Demons or Devil Beasts and to keep Devilman under God's control. Akira returns and reluctantly joins forces with Satan and battles against the forces of God, the winner is not revealed instead ending on a climax of the two great armies drawing to battle.
- Jun Fudo: Sweet, kind, and compassionate Jun was forced into becoming a Devilman; proves to be one of the most capable of all.
- Lan Asuka: A high level psychic who starts off cocky, arrogant and stubborn, slowly becomes more insecure and at times near looses her sanity; never the less, she is proven to be close to Jun, even more so than she imagined when her true origins are revealed.
- Akira Fudo: Originally the main protagonist of the original Devilman and Jun's love interest and companion in her travels through Hell. He informs her of the events he had lived through previously and the foes he had encountered, as well as that God was by no means a benevolent deity.
- Satan: The child of God and also the fusion of Jun and Lan. They betrayed their father and kind after their father tried to wipe out the demon cause.
- Aoi Kurosaki: Jun's past sports rival, after being raped by her stepfather she developed multiple personalities and partially became a Devil Beast. After the beast was killed she became a Devilman and fell in love with Jun, however her schizophrenia still remained and still caused her to try and rape Jun.
- Archangel Michael: God's other child, they are the strongest warrior of the army of God and acts as the off-screen primary antagonist of a majority of the series.
- Seiji Hayami: A police detective who would often assist Jun in cases against Devil Beasts. When the demons returned to earth he was forcibly fused with Kaim.
- Judah Hiroka: The enigmatic and strange leader of the Cult of Dante, really a giant demon of great power.
- Maria: Hiroka's assistant, apparently a strong psychic feline like demoness.
- Dante: Dante the Demon lord was one of the strongest demons in existence.
- Liger: A Devilman who ensures Jun and Lan's safety knowing more than they did of their true origin.
- Unnamed Bird Devilman: A bird like devilman who acted as Liger's partner.
- Zennon: The highly powerful demon Lord that served as Satan's second in command.
- Ryo Utsugi: The reincarnation of Dante Alighieri, Judah Hiroka sends Ryo to Hell where he fuses with the Demon Lord and releases the demons of hell back into the world.
- Sirene: A beautiful demoness who tries to kill Akira in Hell.
- Kaim: A large armored tank of a demon who was a lover of Sirene and assisted her in combat.
- Jinmen: A sadistic turtle demon who could devour people and have them added to his shell. After some time in Hell, his powers only seem to intensify.
- Vlava: A demon with great strength, he was the leader of a great demon army. He claims to have come up with the idea to flood the new human world with the Devilman and Devil Beast threat.
- Masato Fudo: Jun and Hikaru's father and the leading head of the H.A.
- Lagdura: A large female ape demoness who served as Vlava's second in command.
- Medusa: One of the first demons, created accidentally by God, she was killed and sent to Hell where she is frequently seen. Due to this, her beauty vanished and her face turned to resemble an old hags. But when her lover Dante is freed from his icy tomb, she becomes restored.
- Mitsuru: A young Devilman in his late teens, despite his age he was a blood thirsty psychopath who enjoyed killing.
- God: Seen again only briefly, similar to his other appearances he is talked about more than he is actually shown.
Devilman Lady's initial releases were published regularly on Weekly Morning. A side story series, Devilman Ghost was released after the start of the later half of the manga telling the story of Akira Fudo using a ghostly costume to protect Jun. The Devilman Ghost chapters were incorporated into the collected volumes of the main manga at different parts of the series.