The central protagonist of the nine-film series, portrayed as a legendary master swordsman and ninja. Initially introduced as the guardian of the Yagyu Secret Scrolls, he evolves into a one-eyed warrior entrusted with increasingly critical missions to protect the Shogunate, clear his family's name, and defend the Shin-kage style from political conspiracies and martial rivals. Across the franchise, he demonstrates unwavering loyalty, exceptional combat prowess, and a recurring burden of duty that places him at the center of national crises.