The Soryushin Dojo in Evergreen, Colorado is the headquarters dojo for the Takamura ha Shindo Yoshin Kai. The dojo name "Soryushin" literally means "twin willow spirit". This name acknowledges the fact that Shindo Yoshin ryu is the only classical Japanese jujutsu tradition which reflects the lineages of both Nakamura Yoshin Koryu and Akiyama Yoshin ryu. These two distinctly different styles of jujutsu, named in reference to the flexible willow tree were founded in the mid to early 1600's. In 1864, these lineages were combined in Shindo Yoshin ryu by Kuroda Clan retainer Katsunosuke Matsuoka. In addition to Shindo Yoshin ryu, Akiyama Yoshin ryu waza survives today in Yoshin ryu Naginata, Tenjin Shinyo ryu and Ryushin Katchu ryu. Nakamura Yoshin Koryu transmission was lost in the early 20th century so its only remaining waza survives to this day in the Shindo Yoshin ryu.

Toby Threadgill Sensei was awarded a Kirigami Shoden in Shindo Yoshin ryu in 1986.
He was subsuquently awarded a Chuden Menkyo in 1990 and a Joden Menkyo in 1995 by Yukiyoshi Takamura. The Soryushin Dojo was founded at the request of Takamura Sensei in 1996 with Threadgill Sensei appointed dojo cho. In February, 1999 the Soryushin Dojo was appointed western hemisphere headquarters dojo with Threadgill Sensei, the U.S. Shindo Yoshin Kai's senior instructor.

In the summer of 1999, a Menkyo Kaiden for Toby Threadgill was issued by Yukiyoshi Takamura. With the presentation of this license in March of 2001, Threadgill Sensei became one of only three people holding this license and a Gokui Mokuroku.

Between 2001 and 2003, Takagi Iso Sensei, the Japanese branch director and David Maynard Sensei, the European branch director retired from active teaching. With this development, Sensei Threadgill was asked to assume the position of kaicho or administrative head and his Soryushin Dojo selected the official headquarters dojo for the Shindo Yoshin Kai worldwide.

As Kaicho, Sensei Threadgill oversee's regular classes at the headquarters dojo while also maintaining a busy seminar schedule supporting associated Shindo Yoshin Kai dojos and study groups around the globe.