Yagyū Hyōgonosuke (柳生 兵庫助, 1579–1650) or — Toshitoshi (利厳) was the founder of the Owari mainline of the Yagyū Shinkage-ryū style of swordsmanship in the early Edo period.
His name is sometimes mispronounced as Toshiyoshi, but the kanji 厳 reading was passed down as "toshi" in the Yagyū family.
His Zokumyō (first name taken at the time of the Genpuku) was originally Chūjirō, and his Kaimyō (Dharma name) was Jo'un-sai ; though he is mostly remembered as Hyōgonosuke.
Musashi asked, "Aren't you Lord Yagyu Hyogonosuke?"
So instead of measuring each other in combat, Hyogonosuke and Musashi instead conversed like old friends within the house of Yagyu.