Lady Kung Fu (1972)

Korea, 1934. During the Japanese occupation, there is open warfare between rival martial arts schools. There is a fight in the marketplace, and three Chinese students can't stand the unfair way of students that side up with the invasors, when they gang assault one of the fighting men. Between the three, they send the aggressors away. Retaliation is heavy: their school is destroyed, and they are banished. They return to China, and start their own school, and set out on good-will visits to the other martial arts schools, only to find that everybody in their neighbourhood is already dominated by the Japanese. They have many kung fu fights to win, before they eventually manage to establish peace.