Ninja Champion (1986)

"Interpol no longer respects him, violence is the only answer."

A couple camping in the woods is attacked by a trio of thugs and the wife is beaten and raped. A few months after the assault, she is hunting down the three (who happen to be diamond smugglers) by posing as a dealer looking to sell some stolen merchandise. Meanwhile, her Interpol agent husband is doing some tracking of his own in the hopes of bringing them to justice. As they make their plans, a group of ninjas is watching from afar, waiting to make their move.