After the Korean war that ended in 1953 Master Choi started teaching the public - still only teaching out of his school at own home.
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The Hap Ki Do of today is a form of unarmed self-defense based on circular techniques such as jointlocks, foot sweeps and kicks, but incorporating punches and circular throws and a yielding principle similar to that of Aikido, however original Hap Ki Do was actually the exact same thing as Daito Ryu Yawara. The emphasis on circular motion allows for a free-flowing form of combat in which one technique can merge with the next and the direction of force can easily be changed by changing the axis of rotation.