A man named Leon Isaac Kennedy is Doug Russell, an American who steals a shipment of gold in the Philippines with two of his Vietnam War buddies. They cut his throat and threw him into the sea. Russell washes up on an island that has been home to two Japanese soldiers since World War II. They nurse him back to health and teach him martial arts and the art of the samurai to help him fight back. They use their money and ruthlessness to get into the Los Angeles mafia while he's back home in the United States.