Two Japanese schoolboys—short-tempered Ginga Izumo and level-headed Hokuto Kusanagi— meet each other one day, only a few minutes before the Earth is attacked by Galfa, a race of sentient machines determined to wipe out all life in the universe. In the midst of this chaos, the two are chosen by Dendoh, a giant robot built to battle Galfa, to be its pilots, causing them to become members of the Guard Earth and Advanced Reconnaissance organization designated with the protection of Earth from the Galfa advance. The two young pilots find themselves in a race to obtain the powerful and animal-like Data Weapons before Galfa can get their hands on them.