Benkei tai Ushiwaka is a short animated Japanese film made in 1939 by KenzÅ Masaoka. It is based on the legendary encounter between SaitÅ MusashibÅ Benkei, who was collecting swords for the Buddha, and Minamoto no Yoshitsune, who was called Ushiwaka in his youth.
Humanity is under attack by demonic creatures called Oni. Unable to fight back by any other means, the scientist Dr. Saotome creates a series of giant robots that harness the mysterious power of Getter Rays, giving them the strength necessary to fight the Oni. The strongest of these is Getter Robo, and Saotome must enlist three very different men to pilot it - martial artist Ryoma Nagare, criminal leader Hayato Jin, and monk Benkei Musashibou. Together, the Getter Team fights to end the Oni menace forever.
Takes place after the final defeat of the Dinosaur Empire and the death of Musashi Tomoe in the original Getter Robo series.
Dr. Saotome, creator of Getter Robo, fears that the peace the Getter Robo team has won will be short lived and that an even greater enemies would appear. Dr. Saotome's fears are justified when the militaristic Hyakki (or "Hundred demons") Empire appears, but Dr. Saotome is prepared with the creation of an even more powerful Getter Robo, Getter Robo G and a new Getter Robo base. Also with Musashi Tomoe dead, Dr. Saotome needs a third pilot which he finds in baseball player Benkei Kuruma.