During the period of his father, Nobutora, a castle town based on Tsutsujigasaki-yakata (Tsutsujigasaki Mansion) of Kofu district was developed, and the status of daimyo (Japanese territorial lord) during the Sengoku period was established.
甲府の躑躅ヶ崎館を本拠とした城下町が整備され戦国大名としての地位が確立された時期にあたる。