A group of Russians, a Chinese terrorist group and a Japanese ninja are trying to capture a Japanese WWII scientist and steal his formula for germ warfare.

David, an up-coming young master of Ninjitsu, is recruited by his master to steal the formula for a bacteriological weapon and to free the scientist who has developed the evil weapon. He is pitted against two wily opponents: Mark, a KGB operative, and Martin, who claims to be kidnapping Tanaka. The scientist destroyed millions of lives through bacteria experimentation during WWII. Soon, David teams up with Larry who inadvertently saved Mark from David's attack. Once David explains the danger of the formula, the two battle their way through a seemingly endless string of thugs. In the process, they reveal Mark's lot: same as Martin, who's also evil and bent on world domination. David and Larry together with Mark's "nieces", Becky and Brenda, combat with Mark and Martin and their respective bevies of cutthroats in a final acrobatic battle. The fate of man now comes to the hand of these four youngsters.