Reika Minamiya wishes to join the Ancient Girls Unit to find the whereabouts of her missing sister. During the selection, Reika and her friend, Misaki, are caught up in the conflict when the Nergal invaded the Earth. Right at the dangerous moment, G's Frame Shennong suddenly appears before her...

Reika Minamiya is allowed to join the AG Unit as the pilot of the Shennong, but she doesn't know how to operate it. All seems lost when the Nergal attack Borneo Island and the other girls can't escape before they explode. Will Shennong answer Reika's plea?

Following the battle of Borneo Island, AG Unit finally took control of Shennong. Intrigued by the indecipherable signal emitted from this particular G's Frame, the military's top brass decided to send the AG Unit to Jupiter for further investigation. What awaits them on their first mission on space?

After Captain Judith is declared missing in action, Luna takes over as the Ancient Girls' unit leader. It turns out that her father's death was caused by an incident involving a Nergal larva. Will history repeat itself when another Nergal larva infiltrates the girls' spaceship?

After the last Nergal invasion, the energy transmission system connecting the White Giant to Atra-Hasis was badly damaged, which forced them to change course to Mars. Accompanying them is the Destroyer Normandy and its captain, Lieutenant Colonel Peterson, a war hero who fought in the Battle of Mars.

On the way to Jupiter, the girls have to stop by Mars to look for a way to repair the Atra-Hasis' mobile Divine Grace plant. They arrived at the ruins of the ancient alien people who created the White Giant...