Following an accident in the Himalayas, Akira Fudou's body has been taken over by none other than the fearsome demon, Devilman. However, upon living with Akira's relatives, Devilman has come to find himself rather fond of humanity - even if it means getting roughed up by his girlfriend, the Most Dangerous Miki Makimura for acting out, much to the Demon Lord Xenon's dismay. Wishing to kill the traitor, Xenon begins unleashing a series of cruel, grotesque demons unto Earth, and only Devilman stands between them and humanity's demise. Can the reluctant hero save his soul while keeping the city and his secret identity safe?
In a far distant future, professor Hayashi is trying to alert the world to an alien invasion, but is being ridiculed instead. Saved by four dogs his son Tsutomu befriended, the professor transforms the four dogs into cyborgs with incredible abilities. Led by Tsutomu; Queen, Ace, Jack, and Joker will together fight the alien menace.