Shinmen Munisai

, also called Miyamoto Muninosuke, was a martial artist, expert in using the sword and the jitte. He was also the adopted father of the famous rōnin Miyamoto Musashi. He was the son of Miyamoto Musashi no kami Yoshimoto,

Duel against the Yoshioka Sometime after Ashikaga Yoshiteru became the Shōgun, he started in Kyoto a comparison duel between Munisai, who was still called Hirata at the time, and the founder of the Yoshioka-ryū school of sword-fighting: Yoshioka Kenpo (who was also the sword instructor of the Ashikaga). Kenpo won the first match, while Munisai won the other two. This event later started a feud between Munisai's son Miyamoto Musashi and the following generation of the Yoshioka family. Munisai having won the match, the shōgun gave him the title of "Invincible Under The Sun".

Recruited by the Shinmen clan Having heard about Munisai, the head of the Shinmen clan, Shinmen Sokan, recruited Munisai as instructor of his troops. In 1589, for unknown reasons, Sokan ordered Munisai to kill his student Honiden Gekinosuke. After this event, he started training his son Musashi in the ways of the sword and of the jutte, but it didn't last long since the inhabitants of Miyamoto village, displeased with Gekinosuke's death, forced him to move away in the village of Kawakami.