Hap Ki Do is a traditional martial art which has its origins in Japanese Jiu-Jitsu. An orphan boy, Choi Yong-Sool, found himself in Imperial Japan and came back to his native Korea after WWII with this art form. Choi combined his Jiu-Jitsu with the traditional Korean Karate (today known as "tae kwon do") to create this distinctive martial form.