Four psychic teenagers—Mia Alice, Roll Kran, Lamba Nom and Pai Thunder—are brainwashed by the scientist Dr. Tarsan as pilots of his greatest experiment—the giant robot Dangaioh. But as their memories slowly return, these pilots use their abilities and Dangaioh to combat the tyranny of Captain Galimos and the Bunker Space Pirates.

[Source: Anime News Network]

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!

[Source: AniDB]