Suddenly, an evil empire, Jaaku, raids the Earth. But the light appears from the Earth, and fights against Jaaku. It is Raijin Oh operated by Eldran. Eldran has protected the earth since the ancient ages. But he was injured during the fight, and Raijin-Oh falls to the ground. On the other hand, Jaaku scatters their weapons, Aku-Darmer, all over the world.