When a mechanical replica of King Kong is unable to dig for the highly radioactive Element X at the North Pole, the evil Doctor Huu (Eisei Amamoto) and his sponsor Madame Piranha (Madame X in the U.S. release, both played by Mie Hama) decide to kidnap the real Kong. As an insurance policy they kidnap Lt. Susan Watson (Linda Miller) as well as her boyfriend Lt. Jiro Nomura (Akira Takarada) and Cmdr. Carl Nelson (Rhodes Reason). (Kong developed a crush on Susan when she and Nelson visited the Kong at his home on Mondo Island). Kong later escapes and heads for Tokyo. Susan and the others also escape. Huu and his minions follow him and activate Mechani-Kong in order to recapture him. Susan is then grabbed by the robot and is taken to the top of Tokyo Tower and a battle ensues. In widescreen format. (In Japanese language, with English subtitles.)
This version contains footage not seen in the U.S. print and also includes some rare outtakes.