Haja Kyosei G Dangaiou

After a mysterious disaster erases part of Japan, secret preparations begin against a threat from space. Years later, the organization Exstertalon unleashes giant robots in a campaign to subjugate the world.

Alva Base stands against it, with Kuya and his fellow pilots combining their machines into Dangaioh. Each new attack draws them closer to the truth behind the earlier catastrophe and forces beyond their immediate enemy.