Bruce and the Dragon Fist (1977)

In a village in Northern Manchuria, Min-gyu's Taekwondo training hall faces Sujuki's karate hall. With his defeat at a martial arts match, Sujuki loses his pupils to Min-gyu's Taekwondo hall. With growing hostility, Sujuki hires three masked men, Heuk-chun and Hwang-pyo, and has them kidnap Min-gyu's wife, Suk-hi. They torture Suk-hi forcing her to write a letter to her husband asking him to close the training hall and return to his home country. Heuk-chun and Hwang-pyo received from Sujuki a large sum of money for it. They are about to leave when Min-gyu stops and fights them. Along with Jin-pyung, Min-gyu tears down Sujuki's fighting hall and rescues his wife.