Danzan-ryu is a ryu of jujutsu founded by Henry S. Okazaki (1890–1951) in Hawaii. Danzan-ryu jujutsu is common in the United States particularly on the west coast. To quote Professor Okazaki, the founder of Danzan-ryu Jujutsu, "The fundamental principle acquired through the practice of Jujutsu has been elevated to a finer moral concept, the way to gentleness. It may well be said then that the primary objective of practicing Jujutsu is perfection of character. Danzan-ryu Jujutsu teaches the student the importance of one's religion, earth and nature, love of parents and family, respect for teachers and to live in harmony with society.”
Seishiro Okazaki was born in Fukushima Prefecture, Japan in 1890 and in 1906 he immigrated to the island of Hawaii. Soon after, he was afflicted with a pulmonary condition which may have been tuberculosis. It was during this time that Okazaki began studying under Yoshin-ryu jujitsu sensei by the name of Yoshimatsu Tanaka in Hilo, Hawaii. Okazaki intensely pursued his studies under Tanaka and he found after sometime that his respiratory condition had gone into remission. Okazaki felt that the study of martial arts had played a large role in his physical recovery and as a result he decided to dedicate his life to the study and teaching of jujitsu and related disciplines. Later in his life he would adopt the western name, "Henry".
In 1924, Okazaki returned to Japan and underwent a study of the various schools, or ryu-ha, of the then most popular Jujitsu styles of Yoshin-ryu, Namba-Shoshin Ryu, Iwaga Ryu, Kosogabe Ryu, Kodokan Judo, and several others. Later that year when he returned to the Hawaiian Islands, he continued the study of jujitsu under the various masters who had emigrated from Japan to Hawaii. Incorporating not only traditional jujitsu, but also Lua, Shorin-ryu Karate, Eskrima, Boxing, Chin Na and Folk Wrestling, he began to synthesize the most effective aspects of these various styles into an eclectic system which he called "Danzan Ryu". Okazaki used this name to honor his Chinese martial arts teacher, Wo Chong. The Chinese name for Hawaian Islands is T'an Shan; or in Japanese, Dan Zan, which translates as "sandalwood mountain". Hence the term Danzan-Ryu means Sandalwood Mountain School.