Yasuo Yamayoshi

While Kinnikuman is on vacation with Mari-san's kindergarten class at Easter Island, the young wheelchair-bound Kouichi-kun laments being with an idiot like Kinnikuman, preferring to instead be with his favorite Seigi Choujin Buffaloman. Meanwhile, the other Seigi Choujins are also vacationing at ancient landmarks.

Meat-kun has been kidnapped by Iron Mask. In order to save Meat-kun, the treasure of Inmora Island is needed. Furthermore, the treasure is hidden in the Seven Story Tower, which is guarded by the brutal Senshi Choujins. When Kinnikuman asks Terryman and the Seigi Choujins to help him, for some reason they all refuse. Alone, Kinnikuman heads to Inmora Island to fight the Senshi Chōjin and is overwhelmed by their great numbers.

As the whole world watches the Choujin Rugby game on TV, the "Underground Space Emperor" Hydra King has his Underground Space Supermen kidnap Robin Mask. Their aim is to lure out the Seigi Choujins and then attack them using the Robin Memo, which contains info on all of the Seigi Choujin's weaknesses. Watching on TV all over the world, Kinnikuman and the Seigi Choujins get together and head for Planet Hydra.

While Kinnikuman is on vacation with Mari-san's kindergarten class at Easter Island, the young wheelchair-bound Kouichi-kun laments being with an idiot like Kinnikuman, preferring to instead be with his favorite Seigi Choujin Buffaloman. Meanwhile, the other Seigi Choujins are also vacationing at ancient landmarks.

Meat-kun has been kidnapped by Iron Mask. In order to save Meat-kun, the treasure of Inmora Island is needed. Furthermore, the treasure is hidden in the Seven Story Tower, which is guarded by the brutal Senshi Choujins. When Kinnikuman asks Terryman and the Seigi Choujins to help him, for some reason they all refuse. Alone, Kinnikuman heads to Inmora Island to fight the Senshi Chōjin and is overwhelmed by their great numbers.

As the whole world watches the Choujin Rugby game on TV, the "Underground Space Emperor" Hydra King has his Underground Space Supermen kidnap Robin Mask. Their aim is to lure out the Seigi Choujins and then attack them using the Robin Memo, which contains info on all of the Seigi Choujin's weaknesses. Watching on TV all over the world, Kinnikuman and the Seigi Choujins get together and head for Planet Hydra.