Rainy Night Duel.

Masahiko Koseki, a judo master, gets in several fights as a result of protecting a young woman. Despite his success, Koseki is expelled from his judo school because of his propensity for street fighting. He goes to work for a gangster named Joji, but when he realizes that Joji is mixed up in the slave trade, Koseki helps the police in their attempts to foil Joji.