Tsuji Gettan Sukemochi was born to
Tsuji Yadayū descendant of Sasaki Takadzuna, in the second year of Keihan (in 1649, the beginning of the Edo period), in the Miya-mura-aza village area of Masugi, in the Kōka-gun district of Ōmi; what is now Shiga Prefecture. When he was 13 he went to Kyoto to study Yamaguchi-ryū swordsmanship under Sensei Yamaguchi Bokushinsai, and at the age of 26 he received kaiden (full transmission) and opened a school in the village Kōji-machi in Edo; what is now Tokyo. In order to cultivate, train and improve his spirit, mind and body, he went to study Zen and Classical Chinese literature under Zen monk Sekitan at Kyūkō temple in Azabu. At the age of 45 he reached enlightenment and received from his Zen teacher a formal poem taken from the Buddhist scriptures as an acknowledgment and proof of his accomplishment. Tsuji Gettan Sukemochi used the word Mugai from this poem to represent his school of swordsmanship.
It is recorded that among his pupils were Ogasawara Sado-no-kami Nagashige, a very powerful feudal lord, Sakai Kangeyu Tadataka, a feudal lord of a castle in Himeji, Yama-no-uchi Toyomasa, a powerful feudal lord of the Tosa area, as well as 32 daishōmyō, high level samurai having a status slightly lower than that of a feudal lord level with stipends above 10,000 koku, 150 jikisan-no-shi, the Shōgun's direct vassals with stipends below 10,000 koku, and 932 baishin, the vassals of feudal lords.
Tsuji Gettan Sukemochi was unmarried and it is assumed that he had no offspring as he took the eldest son of Head priest Sawatari Bungo-no-kami, of Ōkunitama Shrine in what is now known as the Tokyo provincial government area, as his successor. Shinkan Sawatari (Bungo-no-kami)'s eldest son took the name Tsuji Kimata Sukehide after Tsuji Gettan Sukemochi and thus became Nidai, Tsuji the II. Tsuji Gettan Sukemochi was known not just as a master of the sword, but as an enlightened philosopher and scholar, and his writings Mugai Shinden Kempō Ketsu is recognized as a superb and unique book in Japan's martial arts literature for its depth, flowing style and elegant composition.
Tsuji Gettan Sukemochi died on June 23 in the 12th year of Kyō-hō (1725) at the age of 79. His tomb can be found at Kyūkōji temple, which is in the town of Wakamatsu, in the Shibuya area of Tokyo. The tombs of Tsuji Gettan Sukemochi's successors are kept at the Buddhist priest's cemetery for Nyorai temple, which is in the town of Nishiōi in the Shinagawa area.
The ryū retains both Iaijutsu and Kenjutsu in its curriculum, and has a strong connection with Zen due to Gettan's belief that the "sword and Zen are the way of the same Truth". The name "Mugai" comes from the following poem:
Ippō jitsu mugai
Kenkon toku ittei
Suimō hō nōmitsu
Dōchaku soku kōsei
"There is nothing other than the One True Way
Heaven and Earth profit from this single Virtue
The fluttering feather knows this secret
To be settled during confusion is to be enlightened and pure"