Kinnikuman: Kessen! Shichinin no Choujin tai Uchuu Nobushi

キン肉マン 決戦!7人の超人vs宇宙野武士

A TV Special first aired in 1984. It covers the Planet Rakka story arc and takes place after the 21st Choujin Olympics Arc. A young boy from Planet Rakka named Beansman asks Kinnikuman and the others to help save his planet from the Space Samurais led by Black King. The story was a parody of The Seven Samurai. (Source: Kinnikuman Wiki)