Set in contemporary times, the battle of the Gods (extraterrestrials thought to be Gods by the ancient Greeks) continues.
Hades (in mythology, the ruler of the underworld, embodied by
Dr. Hell) has returned to attack the Earth and exterminate the human race, and to protect it
Zeus sends a robot born from him, Z Mazinger (this is why the Z of Zeus is before the name and not after it as in Mazinger Z, where it's not related to the Greek god).
The robot is given by chance to a student called
Koji Kabuto (the classic Mazinger hero) and together with
Aphrodite (piloted by
Sayaka) and other classic Mazinger characters such as
Tetsuya he defends the planet. Many other gods are involved, and their relationships of love and envy are part of the plot.