Kick no Oni (1971)

An arrogant karate master named Tadashi Sawamura enters the kickboxing ring to prove his superiority, only to be beaten into a coma by a practictioner of the new art. After recovering, his trainer Endo convinced Sawamura to study kickboxing in order to regain his honor. The series is loosely based on the real-life exploits of champion kickboxer Tadashi Sawamura.