Yamato Hino, a young sports enthusiast, hears voices calling out to him and is transported to a parallel world during a thunderstorm. This world is home to the Kingdom of Mu, which is under attack by the evil Dorado of the Dinosaur Empire. Yamato was summoned by the prayers of Queen Aila Mu to pilot a statue known as the God Mazinger. Joining the ranks of the Mu army, Yamato fights against Dorado and his forces.