Skull Man revolves around Tatsuo Kagura, who early in his life was subjected to several mutating science experiments that ended up giving him amazing powers and skills. Longing revenge for the murder of his parents he becomes Skull Man, a shadowy crusader who battles The Syndicate and its evil leader Rasputin.
The story begins abruptly with a woman who possesses immense psychic powers killing a man, only to then be attacked herself by a man who can become a bat, a wolf or an alligator named Garo. Garo is revealed to be Skull Man’s childhood protector and present ally in the coming war against Rasputin and his hordes of evil mutants.
Skull Man makes allies, loses comrades and dies in combat with a lethal mutant just in the first book. What follows is a trip into the world of shadows and the evil within all of us. Throughout his journey Skull Man will face spiders, wasps, scorpions, plants, cobras, vultures, grasshoppers (all based on monsters also featured in the first Kamen Rider series), and finally Rasputin himself