Here Comes Dae Geun(1979)

Original title: 대근이가 왔소

Ship captain Lee Dae-geun falls in love with a showgirl named Eun-shil. When a North Korean spy is refused transport by Dae-geun, the agent atempts to kill him. Lee kills the man in self-defense, but is sent to prison. When released he finds his company bankrupt and his girlfriend being harassed by associates to the slain man. It is up to Dae-geun to save her and his business.