Ninjitsu master Casey is back and out for revenge when his pregnant wife is murdered.

A comet crashes into a Japanese forest and a group of mighty ninjas must fight a group of killer Aliens before they reach their village and kill everyone.

A westerner named Casey, studying Ninjutsu in Japan, is asked by the Sensei to return to New York to protect the legendary Yoroi Bitsu, an armored chest that contains the weapons of the last Koga Ninja.