This book will be analyzing Hapkido Master Choi Yong-Sool's claim to have studied directly under Daito-Ryu Aiki JuJutsu Master Sokaku Takeda, and why this claim to have studied directly from the Takeda family's Daito-Ryu Aiki JuJutsu system is important to establishing not only his legitimacy in teaching the martial art, but also to trace the common roots that Daito-Ryu Aiki JuJutsu, Hapkido and Aikido share by tracing his lineage back to the root tradition.