In 1924 Toyama Kanken moved his family to Taiwan where he taught elementary school and studied related systems of Chinese Ch'uan Fa
(kempo/kwan-bop ), which included Taku (Hakuda in Japanese language ), Makaitan, Rutaobai, and Ubo. Taku is one of central China's Hotsupu (northern school) Ch'uan Fa and is further classified as Neikung Ch'uan Fa (Shorei Kempo), that is, an internal method. Makaitan and Rutaobai, which the techniques of nukite (spear hand) came, and Ubo, all belong to the Nampa (southern school) Ch'uan Fa and are external methods or Waikung Ch'uan Fa (Shorei Kempo). These later three styles hail primarily from Taiwan and Fukuden, China. Toyama sensei was also known to have studied and taught Tai Chi Ch'uan Fa.

Early in 1930 Toyama moved again from Taiwan to mainland Japan and on 20 March 1930 he opened his first dojo in Tokyo. He called his dojo Shu Do Kan meaning "The Hall for the Study of the Way" (in this case the karate-way). Toyama sensei did not claim to originate a new style, system or school of thought, nor did he combine the different styles he had learned. Those who studied under him basically learned Itosu's Shorin Ryu and the related ch'uan fa.

Toyama Kanken, now a Dai Shihan, founded the All Japan Karate-Do Federation (AJKF) in 1946. There is some evidence that the AJKF actually got its start in 1930's, however the federation did not evolve into full fledged organization until it was officially documented and sanctioned in 1946. By establishing an organization such as the AJKF, Toyama's intention was to unify the karate of Japan and Okinawa into one governing organization, providing a forum for the exchange of ideas and technique. The federation became an authority for rank homologation and advancement issuing rank certification, and also created a forum for competition. This competition group later pioneered full contact sparring which used modified ken-do protective equipment (bogu). The AJKF was successful in attracting import, notable people such as Dr. Tsuyoshi Chitose, the founder of Chito Ryu Karate-Do. Dr. Chitose served in several senior positions in the federation including president and vice-president.

Toyama's specialties in karate-do were strong gripping methods (Useishi No Kata and the Aku Ryoku Ho) of Itosu and Itarashiki and similar Chinese methods of finger and hand strengthening. He was the author of books Karate-do Taihokan and Karate-do. In 1949 Toyama was awarded a special title of honor by the Governor of Okinawa, Mr. Shikioku Koshin. Aside from learning Shorin-Ryu from Itosu, Toyama studied and mastered other styles of karate from other notable masters of Naha-te and Tomari-te which also included Okinawan Kobu-do. A few of his other teachers were Aragaki, Azato, Chibana, Oshiro, Tana, and Yabu.

It is also thought that when the Korean (Ch'uan fa) master, Yoon Byung-In came to train at his gymnasium, he also studied Northern Manchurian Kwan-bop with him. It is alleged that Toyama Kanken said that he and Yoon Byung-In should share techniques. Later Yoon Byung-In returned to Korea as a shihan of the Shudokan and taught that style there.

Although Toyama Kanken produced many capable instructors trained in his Shudokan style, he really did not view the Shu Do Kan as a style of karate-do, merely a place for training. Consequently, he did not appoint a successor or Shudokan style head to succeed him and as a result the Toyama system fragmented after his death in 1966.

Master Onishi, a senior student, founded Koei Kan Ryu in 1952. Because of political differences in the national Japanese politics, Toyama gave him permission and full blessing to proceed on his own. Why he did this is not clear as he departed long before his teacher died and was apparently deprived of a very close relationship with Toyama.

After Toyama sensei's death other senior students established their own styles: Toshi Hanaue maintained the original Shu Do Kan; Ichikawa Iso founded Do Shin Kan Ryu (The Heart of the Way Style) in 1969; Michio Koyasu founded Soryu (The All or Complete Style) in 1967. Another notable student was Byong In Yoon- the only Korean listed in Toyama's book, the 1959 "AJKF/ Shu Do Kan register" as a 5th Dan Shihan located in Toyama's book. Byong In Yoon disappeared during the Korean war in the 1950's only to resurface in North Korea in 1995. Two of his students went on to found two of Korea's most important Kwans. Lee Nam-suk founded the Chungmukwon (Hall for the Propagation of Military Training) and Park Chull-hee founded the Kang Duk Kwon (Training Hall for the Teaching of Virtue).