This is the prototype that became Grendizer, before the formula hardened into something safer. A Vegan princess and a Fleedian prince on opposite sides of a war they didn't start, forced to choose between loyalty and love while a giant robot does what giant robots do. Watch it to understand why the franchise mattered, not because it's polished, it's rough and earnest in ways the sequel learned to sand down.

Serving as the pilot film for Grendizer, this action mecha movie centers on Duke Fleed, a fugitive driven from his home planet of Fleed by the forces of Vega. The Vegan armies have not finished with him, and their campaign against the exiled Duke goes on. His story carries a personal wound as well: before war broke out between the two planets, Duke and the daughter of Vega's king were in love.