The siege of Shika castle, which took place in September 1547, was one of many battles fought in Takeda Shingen's bid to seize control of Shinano Province.

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.

The Takeda forces collected the severed heads of 15 samurai and around 300 ashigaru from the battlefield at Odaihara and subsequently paraded these round the walls of Shika in a bid to intimidate the garrison into surrender.

[2] The fall of Shika spurred Murakami Yoshikiyo, the most powerful Shinano daimyō, into moving against the Takeda, and in 1548 he succeeded in defeating Shingen at Uedahara.