During a championship baseball match, the three brothers hear that their grandfather in Japan is in trouble, and head out to help him, conceding the match. When they arrive in Japan, they must use all their powers to defend him against his ancient enemy, who has returned to exact revenge.
Rocky, Colt and TumTum must battle an evil wealthy toxic waste dumper in order to save a local Indian tribe and their friend Joe. The 3 Ninjas must help find Joe's father and find a secret disk that contains evidence that could stop the toxic landfill that is destroying the Indian community....
