Katsuyori chose Iwadono-jo Castle, the residential castle of Nobushige OYAMADA, Kokujin of Kai Province because it was in Takeda family' domain (According to one theory, the residential castle of the Oyamada clan was Tanimura-jo Castle and Iwaki-jo Castle located in the territory of the Oyamada family was under the direct control of the Takeda family).
勝頼が選んだのは武田家の本領である甲斐国人・小山田信茂の居城である岩殿城であった（注：小山田氏の居城は谷村城で、岩殿城は小山田領内の武田家直轄の城であるという説もある）。