When a martial arts hero is taken hostage, three young ninja brothers team up to rescue him from an evil bandit queen. Rocky Douglas and his two younger brothers are visiting the Mega Mountain Amusement Park for a day's outing. At the park, a once popular TV star is giving a martial arts demonstration.

But the vicious Medusa and her henchmen have plotted to take over the park by force and demand ransom for it. To stop the takeover, the young boys team up with their martial arts hero to battle Medusa and free the park.