Dai-Guard: Terrestrial Defense Corp.

The two Heterodynes that attacked Tokyo have merged into one, with Kokubogar and its main pilot Iizuka trapped inside! Whilst the others search for the now missing Akagi, Shirota takes on the role of main pilot, and plans a joint operation with the army to contain the Heterodyne until Domeki's latest weapon can arrive to finish it off and save Iizuka.