To prepare for the Oda and Tokugawa allied forces that would carry out an attack in the near future, Katsuyori built Shinpujo-Castle in Nirasaki which was stronger than Tsutsujigasaki-yakata (Tsutsujigasaki Mansion) for the purpose of solidifying the defense and reorganizing Takeda's army.
勝頼は、近い将来攻め込んでくるであろう織田・徳川連合軍への備えのため、躑躅ヶ崎館より強固な韮崎の地に新府城を築城して防備を固めるとともに、武田軍団の再編成を目指した。