Obukan Judo traces its beginnings to a demonstration of Kito-ryu Jiujutsu given by Bunzaemon Nii and an unknown opponent at the Lewis & Clark Exhibition of 1905. This demonstration and the efforts of Nii sensei and the Japanese American community resulted in the formation of Portland Judo Club in 1926 (later Obukan Judo Dojo, Inc.). Nii sensei was chosen as Obukan’s first instructor.

Dr. Jigoro Kano, the founder of Judo, visited Oregon while touring the United States after the 1932 Olympics in Los Angeles. Portland Judo Club hosted a shiai (tournament) in his honor. At a meeting afterward Kano shihan officially changed the name of Portland Judo Club to Obukan Judo Dojo. The “O” refers to Oregon; Oregon was called “O-shu” or O-state by Japanese immigrants. “Bu” means martial training. “Kan” means building or training hall.