The origin of Aiki-ken can be traced back to Morihei Ueshiba, the founder of Aikido, and his study of various martial arts styles throughout his life. Some of the major ken-related arts that Ueshiba had exposure to include Yagyu Shinkage Ryu 柳生新陰流, Yagyu Shingan Ryu 柳生心眼流, Daito Ryu 大東流, and Kashima Shinto Ryu 鹿島新当流. In 1902, when Ueshiba was 19, he moved to Tokyo to start a stationery business but returned to Tanabe in less than a year due to a health problem. It was during this short period of time that he trained in Yagyu Shinkage Ryu, but it is unclear who his teacher was. Yagyu Shinkage Ryu was…