The alien invader Goa plots to conquer the Earth. He first warns the Murakami family (father Atsushi, mother Tomoko, and son Mamoru) of their invasion, and demonstrates his powers by transporting them to a prehistoric jungle and destroying a Giant Dinosaur before their very eyes. But they will not agree to surrender to Goa, so hope comes in the form of Magma, an armored, golden giant with long hair and antennae. He and his human-sized wife Mol, both created by the wizard Earth are sent to defend our world against Goa. They befriend Atsushi and Mamoru, the latter has Magma emotionally touched, as he wanted to have a child with his wife Mol, so Earth creates a duplicate of Mamoru, named Gam Earth gives Mamoru a whistle, with which he can call Gam Mol and Magma in times of crisis. So when Goa unleashes his various daikaiju, chances are, Magma, Mol, and Gam will fly to the rescue.

Many people have fond memories of meeting a certain teenage boy in their younger years. However, their ages vary widely, and each remembers him as a teen. This story follows the intricate intertwining of their various stories and how this young man, who apparently lives outside of time, has affected each of them.

The OVA will be pre-sold during the Comiket 87 starting on December 28, 2014, regular retail distribution of the limited edition package will start on January 30, 2015.

The story focuses and revolves around the 108th Guard Squad, stationed in Aomori. A poorly equipped unit with very little military standing, it is often viewed as a 'reject camp' for pilots not making the grade for the elite units based in Hokkaido. The apparent helpless nature of this force is hardly a deterrent for the encroaching enemy armies, ever closing in on both the 108th and the rest of the empire. The young pilots of the 108th, who had dreamed on returning home, are plunged forcefully and unwillingly into a war.