At sometime between 1946 and 1950, Mas Oyama trained at Kanbukan, a dojo founded by high ranking students of Kanken Toyama known for its large degree of Zainichi Korean membership. Nei-Chu So was also an active trainee at Kanbukan and likely taught Goju-Ryu to Oyama there. In Kanbukan, Karate was practised with Bōgu/protective gear (Bogutsuki Karate), which allowed for delivering strikes with full force, and may have influenced Oyama's full contact fighting mentality. However, sources say that Oyama had little interest in Bogutsuki Karate as a sport.Jinsoku Kakan. (1956). Interview with Gogen Yamaguchi about karate-do. Tokyo Maiyu.Kinjo Hiroshi from "Overview of Kenpo" by Nisaburo Miki and Mizuho Takada "Commentary on Reprint of "Overview of Kenpo" p. 265
