Kinnikuman: Gyakushuu! Uchuu Kakure Choujin

While the world watches a Choujin rugby match, Robin Mask is abducted by the forces of the Underground Space Emperor, Hydra King. Their real weapon is the Robin Memo, a record containing the weaknesses of Kinnikuman and the other Justice Choujin. With Robin as bait and their vulnerabilities exposed, Hydra King prepares an ambush designed to eliminate the heroes at once.

Kinnikuman and his allies gather from across the world and head for Planet Hydra to rescue their friend. There, the information stolen from Robin turns every familiar strength into a liability, forcing the Justice Choujin to overcome opponents who already know exactly how to break them.