Michio Koyasu 道雄小安, a Toyama protégé, was born on 5 December 1925 (Tai Sho 大正14) in Tokyo, Japan as Kiro Nagayama 喜郎永山. His father, Kiichi Nagayama 喜一永山, was a Major in the Japanese Imperial Army was killed in action 1941. His grandfather, a carpenter, was from Aomori, Japan. Initially Koyasu’s father taught him Japanese Kempo 日本拳法 and Bai Shin Ryu Ju- Jutsu 梅心流柔術. Later when Koyasu Sensei was 13 in 1938 his father enrolled him in Karate-Do under the tutelage of Kanken Toyama Sensei in Tokyo. While he was studying Karate-Do and to diversify his knowledge of the martial arts, young Kiro Nagayama also studied, Kodo Kan Ju-Do 講道館柔道, Ken-Do 剣道, and Tai Kyoku Kem-Po 太極拳法 Tai Ji Quan Fa.
During World War II, Nagayama served in the Japanese Imperial Army as a sergeant. He was stationed and served most of his time at the military academy in Tokyo. After the war he moved to Matsu Ura, Japan, where his father had been previously stationed, to start teaching Karate-Do and establish a new Karate-Bu. Initially, for financial reasons, Koyasu established the Koei Kan 幸栄館 a branch of Sensei Eizo Onishi’s 栄三大西 organization where he taught Karate-Do and Chinese Kempo. This arrangement was suggested and fostered by Dai Shihan Kanken Toyama to assist the financially strapped Michio Koyasu. Koyasu Sensei, at the bequest of Toyama Sensei, was mentored by Eizo Onishi the Soritsusha 祖立者 founder of the Koei Kan from the late 1940’s till Onishi Sensei separated from Toyama Sensei. Later, when he could afford the incorporation fees, he renamed his school Soryu Kan 総流館 the complete style hall based on his ideas and philosophy. In 1958 the Soryu Kan was incorporated by the Ren Bu Kai in Shin Juku, Tokyo, Japan. At this point Koyasu Sensei embarked on the development of what would eventually become Soryu Karate-Do. On 7 February 1950 Nagayama was promoted to Go Dan 5th degree, Shihan master instructor and was given the Bu-Do name Michio Koyasu by Toyama Sensei. Koyasu Sensei continued this tradition for his students that earn Go Dan Shihan. Four or five years later (1954 or 1955), he moved to Sasebo, Japan where he re-established the Soryu Kan Karate-Bu 空手部 Karate club and established the All Japan Karate-Do Federation (AJKF) regional headquarters. Soryukan 総流館 the complete style hall was part of Toyama’s Seito Okinawan Karate-Do until after Toyama’s death in 1966 when Koyasu officially established Soryu 総流 as an official style. Koyasu Sensei was promoted to Roku Dan 6th degree on 5 May 1958, to Nana Dan 7th degree on 29 July 1962 and to Hachi Dan 8th degree in 1965 and was conferred the proficiency title Saiko Shihan 最高師範 Supreme Grand Master. In 1967 Koyasu Sensei became Soke 宗家 Head of Family when he founded Soryu Karate-Do. Toyama Sensei had always expressed that he did not want his Dojo name to be used as a name of a style of Karate-Do, which is probably why he never named a successor. Toyama firmly believed there were no styles, that Karate was just Karate. Koyasu Sensei had great admiration for his Sensei and felt a strong obligation to follow his wish. He had many different and innovative ideas about what and how Karate-Do should be taught. Koyasu Sensei not only was a federation regional director but also served on the AJKF board of directors as one of its vice-presidents. In 1987 when the AJKF divided due to political differences Koyasu Sensei founded The All Japan Soryu Karate-Do Federation (AJSKF) which became an international style based organization. The federation headquarters is still located in Sasebo whereas the Japanese national Soryu Karate-Do headquarters Dojo was relocated back to Matsu Ura in the Ken Ryu Kan 拳龍館 Dragon Fist School in 1984 headed by Yukihiro Ikeda a.k.a.Michihiro Koyasu 道博小安. The Shin Ryu Kan 心龍館 Dragon Spirit School headed by James A. Caldwell a.k.a. Tatsuo Koyasu 龍雄小安was established as the United States headquarters in September 1991. A short time before Koyasu Sensei’s death the headquarters was moved back to Sasebo and Emiko 恵美子, Michio Koyasu’s wife and partner, assumed the head of the federation. Emiko Koyasu had held the position of Executive Office Director and also teaches Tai Kyoku Kempo. It was also an expressed wish of Koyasu Sensei that Emiko become Soke of Soryu Karate-Do. After Koyasu Sensei’s death, due to inappropriate behavior, Yukihiro Ikeda was expelled from the organization and his Ken Ryu Kan Dojo in Matsu Ura was closed. Takashi Nakamura a.k.a. Takamichi Koyasu 孝道小安 was appointed as the Shihan Toku 師範督 Chief Instructor. In 2010, Toshiyuki Hasagawa 敏幸長谷川 was asked to take over the teaching duties of the Soryu Kan Dojo in Sasebo, Japan. He is also the Vice-Chairman of the Federation. Although the All Japan Karate-Do Federation no longer exist Dr. Chitose’s Chito Ryu and So Ryu still maintain a close relationship in Japan today.
Koyasu Sensei admired many of the great masters of Karate-Do and tried to follow their teachings, including Gichin Funakoshi. He felt in some ways the same way Funakoshi and Toyama Sensei’s did about Karate-Do. One of these was that there should be only one Karate-Do and it should not be broken into many styles. Koyasu felt so strong about it that he developed Kata such as Bai Rei 梅霊 The Spirit of a Plum Tree that employs the best techniques from many of the major styles of Karate-Do. He felt developing Kata like this would help unify Karate-Do. He did away with a lot of the aesthetic techniques used in Kata and adopted the techniques that would be most useful in Kumite.
 Information for the Michio Koyasu biography was obtained through personal interview by James A. Caldwell, updates from the Soryu Karate-Do HQ and Soryu Karate-Do Federation Training Materials.