Shinmen Munisai (新免 無二斎), also called Miyamoto Muninosuke, was a martial artist, expert in using the sword and the jutte. He was also the father of the samurai named Miyamoto Musashi. He was the son of Miyamoto Musashi no kami Yoshimoto, a vassal of Shinmen Iga no Kami, the lord of Takayama Castle in the Yoshino district of Mimasaka Province. Munisai was relied upon by Lord Shinmen Sokan,the head of the Shinmen clan and so was allowed to use the Shinmen name. He was one of the few to have obtained the title of "Unrivaled Under The Sun", title offered to him by the Shōgun Ashikaga.
Munisai founded his own ryūha: the Tōri Jitte Ryū, which was one of the schools taught to his son Miyamoto Musashi, who conceived the Hyōhō Niten Ichi-ryū.
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