Revenge of the Ninja is a 1983 martial arts-action-thriller film starring martial artist and cult actor Sho Kosugi as a ninja trying to protect his only son from a cabal of ruthless gangsters. It is considered part of the so-called "ninja trilogy", starting with Enter the Ninja (1981) and ending with Ninja III: The Domination (1984), though none of the films have any connection to one another besides the presence of ninjas and actor Kosugi appearing in different roles. It was directed by Sam Firstenberg and also stars Keith Vitali, Virgil Frye, and lead Sho Kosugi's son, Kane Kosugi. The film has since become a minor cult hit due to its elaborate martial arts sequences and B-movie production values.
(Summary from Wikipedia)