Lord of the Karatsu Clan in Kyiishii, he was commonly called Keishichiro. Eldest son of Nagamasa. Went to Edo (1838) and became well known for his perspicacity. In 1857, he became the son-in-law of Nagakuni Ogasawara and ably ruled his clan for four years. After returning to Tokyo (1872), he spent his remaining years in quiet seclusion.