The History of Tenshinryu 

Tenshinryu is a traditional Japanese martial art that originated approximately 400 years ago in the early Edo period. Tokizawa Yahei, who served Yagyu Munenori, developed this style under Munenori’s orders.
Yagyu Munenori was an Ometsuke(*) of the Tokugawa shogunate. Tenshinryu was devised for use by the Kogan(光願), a group of warriors(Shirindan 士林団) under Munenori who supported the Tokugawa shogunate from the shadows. Kogan means “wish for light”, which means to pray for the continued peace of the country.
*The Ometsuke is an inspector who monitors the feudal lords and the Imperial Court and protects the Shogunate from these rebellions.
Tokizawa Yahei organized and systematized the wisdom and techniques of various schools and covert practitioners, as well as the ingenuity of Munenori, based on the Yagyu family’s Shinkageryu, and named it Tenshinryu.
However, the work was lost as peace prevailed, and it was dissolved during the reign of the 8th shogun, Yoshimune. Some of the styles were publicized in the Kansai region and taught at clan schools. (This line has ceased to exist.) However, some of Kogan’s samurai preserved the Tenshinryu to work, once again, for the Tokugawa shoguns when peace was once again disturbed.
The descendants of one of Kogan’s first kumigashira(組頭 small group top), Ishitsunemon, continued to preserve Tenshinryu in the Kanto region. The 8th generation of the Tenshinryu, Ishii Seizo, succeeded him and passed it on to the 9th generation, Nakamura Tenshin.