After the Ōnin War (1467–77), the shōgun's system and taxation had increasingly less control outside the province of the capital in Kyoto, and powerful lords (daimyōs) began to assert themselves.

Bordering Kai to the north was Shinano Province, a large mountainous territory which was not controlled by a single clan but by several relatively weak ones, notably the Suwa, Ogasawara, Murakami [ja] and Takato.

Fresh from the defeat of the Sadakiyo, he then turned his attention to Shika castle, controlled by Kasahara Kiyoshige, which he laid siege to on 8 September 1547.

[3] While besieging Shika castle, Shingen detached a part of his troops and met the forces of Uesugi Norimasa on the plains of Odaihara.

The parading of the severed heads from the Odaihara battlefield is famously depicted in the 1969 Japanese film Fūrin Kazan ('Samurai Banners'), which follows the careers of Takeda Shingen's general Yamamoto Kansuke.