Synopsis

Mari and Kinnikuman's Championship Belt are stolen by the Octopus Dragon and his minions. Now Kinnikuman and the other Justice Choujins must travel to Planet Metro and compete in a tournament in order to win them back.

"Kinnikuman (1984), also known as Kinnikuman: Stolen Championship Belt, is the first theatrical film of the anime series Kinnikuman. It was released in Japan on July 14, 1984 and is set after the 21st Choujin Olympics Arc. This was the first movie to feature seiyuu Kouji Yada, who appears in all following movies (except the final two), and also the first to feature series creators Yudetamago in a cameo. Octopus Dragon, Harigoras, and Ukon are all kaijuu from the infamous \"Roots Island\" two-part story from the original manga that does not appear in recent reprints. Tigerian is also a kaijuu from the original manga, although these characters bear little resemblance to their manga counterparts. The movie's monster Gigasaurus does resemble the manga's Octopus Dragon. (Source: Wikipedia)"