Shigenari (or Oribe) FURUTA was born in 1544 as a son of Shigesada FURUTA, a tea ceremony master (known by his Buddhist name Kannami of tea-server, he later renamed himself Shigemasa SHUZEN as he returned to secular life), who was also a younger brother of the Lord of the Yamaguchi-jo Castle in Motosu-gun County, Mino Province (whose name is believed to have been Shigeyasu FURUTA).
天文13年（1544年）、美濃国本巣郡の山口城主（古田重安？）の弟で、茶人の古田重定（茶坊主の勘阿弥、還俗し主膳重正と改名）の子として生まれる。