Emperor Guillotine sends Dr. Over and Ligon, a new weapon in the shape of a pyramid, to the earth. By operating Ligon, Over destroys oil fields in Araia one after another. The price of oil soars in all countries and the world economy is thrown into confusion. Then the doctor tells Hishino, a Japanese oil engineer in the Arabian Desert to help him. Hishino refuses, and he is imprisoned in Ligon together with Arabian members of Unicorn Organization. Suspecting that all the trouble was caused by BF Syndicate, the head of the Japanese Branch of Unicorn Organization sends two members -- Minami and Mitsuko, Hishino's sister -- to Arabia. On the way their plane explodes, but they are rescued by Daisaku (Johnny Sokko) and Giant Robo who have been following the plane.
