Following the battle with Demaaga, Gento can not hide his confusion about the alien being that resides in his own body. That's when a meteorite flies in from outer space. It lands on Earth, evading the GGF's attempts to intercept it, and transforms into the kaiju Gebalga. It seemed that Earth Garon would have the upper hand in the fight until Gebalga revealed it's surprising ability...

As the network contamination by Gebalga continues to spread, SKaRD plans a new operation. Gento is distrustful of Blazar, who has once again acted against his will in the battle against Gebalga. He decides to leave the Blazar Stone in his locker. SKaRD decides to commence a major joint-operation by combining forces with the development team and the special forces unit.

Teruaki rushes back to his parents' home when he hears that his father has fallen ill. However, this turns out to be a lie just to get Teruaki back home. Teruaki's father wants Teruaki to quit the GGF and the divide between him and Teruaki grows further. This is when they hear strange chirping from insects. Apparently, the quality of the soil in the fields has changed over the past month and the crops are dying. As Teruaki and his father go around, they find a strange cave in the mountains...

The fifth flight test of the Earth Garon Mod. 3 begins with Yasunobu as the pilot and Anri in the commander's seat. They reach the maximum speed of Mach 9 during aerial combat maneuvering. However, Yasunobu is unable to withstand the gravitational acceleration and loses consciousness. Because of this, he is discharged as the pilot of Mod. 3. In the meantime, a gigantic Deltandal appears, and Anri and Earthy are forced to pilot Earth Garon.