Shogo Kuniba was a student of Ishii Gogetsu, the 14th Soke of Mugai Ryu Iai Hyodo under Nakagawa Shinichi (13th Soke). It appears that Ishii and Nakagawa Soke had a parting of ways and Ishii left Mugai Ryu.

Nakagawa Soke never did appoint a 15th Soke, but Shiokawa Hosho Sensei was widely regarded as the 15th Soke. Shiokawa Soke also appointed 4 successors to oversee Mugai Ryu Iai Hyodo, all of whom will share the title of 16th Soke. Also, it is understood that Shiokawa Soke appointed one Okazaki Sensei as the 16th Soke, after the other four broke of from him.

Today there are several branches of Mugai Ryu, with atleast 9 poeple known to lay claim to be Soke.
Some of the new branches have introduced new kata and incoporate the kata from other modern styles in order to promote sports and competitions. Other smaller groups still focus on the traditions of the older style of Mugai Ryu.

Even the Iai Hyodo as organized and taught by Nakagawa Shinichi is consdiered by some to be a new version of Mugai Ryu. Even though it was much more of an effort to preserve and carry traditional Mugai Ryu into the future, as opposed to changing the art to make it into a modern adaptation of an ancient art. As I understand, there are still representatives of the Takahashi family in Kyoto teaching a pre-Nakagawa version of Mugai Ryu.

Kuniba Soke was a student of Ishii Gogetsu, the 14th Soke of Mugai Ryu Iai Hyodo. Although we refer to Kuniba Sensei as "Soke", it is important to note that he was not Soke of Mugai Ryu. It was through students of Kuniba Sensei that I learned the kata. I was also able to absorb a good amount of general sword knowledge from my Jujutsu teacher, Darrell Craig Sensei of the Houston Budokan - although I was not a formal Mugai Ryu student of Craig Sensei. Craig Sensei, the author of "Mugai Ryu Iaijutsu" was a student of Shogo Kuniba and also received some instruction from Nakagawa Shinichi Soke, Haga Sensei and possibly others.

As for Mugai Ryu in the United States, Sakimukai Sensei is the only known teacher in the U.S. to have received Menkyo Kaiden. This was granted to him by Shiokawa Soke. Sakimukai Sensei teaches in Jacksonville, FL.

Darrell Craig of the Houston Budokan still teaches Muagi Ryu. The American Goshin Budo and Kobudo, which was set up by Shogo Kuniba still teaches Mugai Ryu. There are also other students of Kuniba Sensei who still teach in the U.S. Kai Kuniyuki Sensei, one of the 16th Soke had a student in the U.S. who was teaching, and there may still be a class some where. Other than that, there is a group headed by Ryusuke Juge Sensei in Canada that is affiliated with Kuniyuki Sensei. For those interested in modern competition Mugai Ryu, there is the new Meishi Ha Mugai Ryu that has a U.S. headquarters in California.