Hiroshi Shiba is an outstanding car racer whose father is assassinated upon the discovery of the Bronze Bell from an ancient civilization. This Bronze Bell is coveted by Queen Himika who comes from that ancient era; the Yamatai Kingdom, and whose ambitions are to seize the Bell and dominate earth.

Hiroshi is left with a few items from his father which would enable him to morph into a full sized mecha warrior, the Steel Jeeg. With these abilities and the help of his father's brain implanted in a computer and his assistance Miwa "Micchi" Uzuki, they set out to neutralize Himika's plans of world dominion.