Haru, an orphaned American who washes ashore in Japan and is mistaken for the great White Ninja of legend. Raised among the finest Ninjas, Haru grows strong and big – very big. With the grace of all Three Stooges rolled into one body, Haru is an embarrassment to his clan. But when a beautiful blonde pleads for his help, Haru is given one dangerous, disastrously funny chance to prove himself.
After completing his training of ninjutsu within Japan, an American Vietnam veteran by the name of Cole (Franco Nero) visits his war buddy Frank Landers (Alex Courtney) and his newly wed wife Mary Ann Landers (Susan George), who are the owners of a large piece of farming land in the Philippines. Cole soon finds that the Landers are being repeatedly harassed by a CEO named Charles Venarius.
A female aerobic instructor is possessed by an evil spirit of a fallen ninja when coming to his aid. The spirit seeks revenge on those who killed him and uses the female instructor’s body to carry out his mission. The only way the spirit will leave aerobic instructor’s body is with the help of another ninja.