In a future where pollution prompts the rise of hydrogen fuel and humanity seeks refuge on Mars, Earth falls to the Inbit alien invasion. With survivors fleeing to the Moon and Mars, Lieutenant Stick Bernard, fueled by vengeance after losing his fiancée to the Inbits, leads a group of rebels on a mission to reclaim Earth. Along the way, they uncover the Inbits' true intentions, leading to a desperate race against time to avert mutual destruction. As tensions escalate, Stick and his allies must navigate a dangerous landscape of evolving threats and alliances, including encountering human-like Inbits, in a quest to persuade the Inbit ruler to abandon Earth. Amidst the chaos, powerful mechas like the MOSPEADA and the Armo-Fighter AFC-01 Legioss take center stage, shaping the fate of both species in this epic battle for survival.