Mikogami Tenzen (神子上典膳) or Ono Jiroemon Tadaaki was a Japanese samurai of the early Edo period, who was renowned as a swordsman.
He was one of two official sword masters for Tokugawa Ieyasu and his style, along with Yagyū Shinkage-ryū became one of the official ryūha of the Tokugawa Shogunate.
Tenzen (典膳), meaning assistant cupbearer (for the Emperor) seems to have been a court title under Ritsuryō system, Tadaaki got as an honorific from the Bakufu.
In Eiji Yoshikawa's book Musashi, Tadaaki appears as an aging samurai, instructor to the Shogun.
He then withdraws from public life and goes to live as an hermit.