Prince Kinnikuman, who came to Earth from Kinnikusei, a planet at the end of the universe, was always ridiculed by humans as a useless Chojin. However, by chance, he was given the right to participate in the Chojin World Cup, a tournament to determine the world's best Chojin, and by a miracle, he won the championship. The following year, he even won it again!
Since then, he has become a central figure among Seigi Chojin who protects the peace of the universe. He has managed to defeat the raging forces of the enemy, including Akuma Chojin who plans to rule the world, and Perfect Chojin who aims to wipe out the weak Chojin on Earth, with the power of friendship with his friends, including Terryman and Robin Mask.

In recognition of his achievements, Kinnikuman wins the "Survival Match for the Kinnikusei Throne," the final test of his career, and is crowned the 58th Great King of Kinnikusei! He returned to his home planet from Earth, got married, and said goodbye to eight years of fighting. About a year and a half later, the entire universe was supposed to be at peace...