Natori Sanjurō Masatake (born around the 1630's) was a samurai, a teacher of military strategy, and an exponent of ninjutsu. He is most noted for having written the Shōninki, a ninja training manual, and for founding the Kishū-Ryū school of martial arts. Natori went by a number of names during his life, including Natori Masazumi, Fujinosshuishi Masatake and Fujibayashi Masatake. His date of death is uncertain, but has been given in some sources as 1708.