American Ninja
Joe Armstrong is a quiet GI with a big secret behind him: he perfectly masters the martial art of the Japanese ninjas - the mysterious shadow warriors, in whose hands everything becomes a dangerous weapon. Who taught him the deadly techniques and tactics of the ninja is unknown to Joe due to a memory clouding. A mystery, however, that is solved when Joe's determined intervention ruins a fraudulent arms deal between his superior Colonel Hickock and the Mafia boss Ortega. For it is during this raid that Joe first encounters a black ninja for whom killing has become a business. A dirty business, which Joe confronts with all the possibilities of ninja martial arts....
American Ninja 2
On a secret mission, Rangers Joe Armstrong and Curtis Jackson land on a small Caribbean island to investigate the mysterious disappearance of Marines. Already during their first investigations they clash with ninja killers working for a crime syndicate. They find out that the kidnapped marines are being transformed by a genetic researcher into will-less, bloodthirsty fighting machines at the ninja headquarters. Armstrong and Jackson now try by all means to excavate the ninja nest and free the prisoners - but the ninja robots are already waiting for them. Armstrong confronts the ninjas' master teacher and fights a battle to the death with Tojo Ken....
American Ninja 3 - Bloodhunt
U.S. karate champion Sean Davidson travels with his teammates to a small Caribbean island to participate in a competition. There, a terrorist named "Cobra" is up to his tricks, experimenting with genetic manipulation and possessing an invincible ninja army. When Sean is forcibly injected with a virus that turns him into a will-less fighting machine, his friends Jackson and Dexter try to free him from the criminal's clutches.
American Ninja 4 - The Annihilation
An elite U.S. Delta Force special forces team is captured by black ninjas during a secret mission in the African highlands. The kidnappers make a ransom demand in the billions and threaten to shoot the prisoners and destroy New York. Top agents Sean Davidson and Carl Brackston are tasked with freeing the hostages from the terrorists' grasp. But Davidson and Brackston are also overpowered. They are to be shot along with the others if the U.S. government refuses to pay the ransom. Now only one can help them: Ex-top agent Joe Armstrong. But the "American Fighter" has retired....