Born in Muroran, Hokkaido, Japan, Yonezawa Katsumi had a career as a junior high school principal. In addition to karate and judo, he studied Daitoryu Aikijujutsu under Horikawa Kodo, Meijin and became one of his uchi deshi. In 1988, he was promoted to 7th dan, and was promoted to Shihan in October of 1994 (Heisei 6th year). In 1995, Yonezawa was permitted by the Daitoryu Kodokai to become Menkyo Kaiden Shihan of Daitoryu Bokuyokan to lead the Bokuyokan as an independent Daitoryu organization. Fluent in English, he was the first person to introduce Daitoryu Aikijujutsu Kodokai in the U.S. in the early 1970’s. Yonezawa Shihan traveled to the U.S., Mexico and Canada teaching Daitoryu, and is one of the primary people responsible for the dissemination of Daitoryu Aikijujutsu Kodokai in North America. He established the Bokuyokan Dojo in Muroran, Hakkaido, Japan which was a Kodokai Shibu from 1975 through 1995. In September of 1995, the Bokuyokan Dojo became the headquarters for the Daitoryu Aikijujutsu Bokuyokan. Branches in the U.S. and Germany were established in 1996, and a Canadian branch followed in 2006. Yonezawa Soshi Shihan was succeeded in the Bokuyokan by his son Hiromitsu Yonezawa, Nidai Soke.