Clash of the Ninjas (1986)

An illegal organ donor ring (the involuntary kind), run by ninjas, is operating Hong Kong. It's up to Tony, a plucky Interpol agent, to bring them to Justice. When the head ninja (who killed Tony's master years ago) also kills his girlfriend, tony really gets fierce. Turns out Tony is a ninja, too (the good kind), and there's a climactic battle at the end where good explosively triumphs over evil.