A mysterious explosion on Futagami Island begins a new chapter in the Dangaioh mythos! Led by the evil Professor Katou, a band of warriors calling themselves the "Tartarus Knights" have begun their campaign to lay waste to the world by way of a small research station on Futagami Island. Katou's victory seems almost certain until he encounters an advanced fortress guarding the island. From it, a group of three humanoid robots are launched—Dangaioh!

Initially planned to have an episode length of 26 episodes, production was cancelled after episode 13, due to the poor reception of the series.