The Iwamatsu clan was requested to present its traditional family tree of the Nitta clan, however, it refused the request, and was awarded 120 koku in Tajima-go, Nitta District, Kozuke Province, and survived as a kotaiyoriai (alternate yoriai, a family status of samurai warriors in the Edo period).
伝来の新田氏系図を進上するよう求められたがこれを拒否し、上野国新田郡田嶋郷内120石の禄を与えられ交代寄合として存続した。