A mighty robot named Golion misuses his immense powers to vanquish Deathblack Beastmen, believing himself unbeatable. In response to his hubris, a celestial entity divides Golion into five lion robots as punishment. Fast forward to 1999, where a quintet of young astronauts returns to a war-torn Earth post-nuclear devastation. Confronted by the alien Galra race, these men are whisked away to the planet Altea, discovering that the dormant lion robots reside scattered across Altea. Their mission now: revive the lions and unite them to reconstruct Golion, the last chance for humanity's survival.