He was the fifth son of the swordsman Muneyoshi YAGYU (Sekishusai), a local lord of the Yagyu Village in the Yamato Province, who was conferred full mastership in the Shinkage-ryu (Shinkage school of swordsmanship) from Nobutsuna KAMIIZUMI in 1565.
大和国柳生の領主で、永禄8年（1565年）に上泉信綱から新陰流の印可状を伝えられた剣術家・柳生宗厳（石舟斎）の五男。