Suddenly, the peace of the world is thrown into danger by Mogool, an undersea stronghold resting on the ocean floor. Helqeen, the tyrannical ruler of the Mogoolian Empire, plots to conquer the Earth together with her devoted companions Goroskie and Zan-gack. Anticipating this terrible event, Dr. Yuri forms the Blocker Corps, organizing four powerful robots to oppose them, and brings together four individuals who possess the extraordinary ability called "elepath"—a power for piloting enormous robots. Thus begins a desperate life-or-death battle between the Blocker Corps and Mogool, as a long series of fantastic and magnificent clashes unfolds.