Takeda Katsuyori, the son of clan head Takeda Shingen, led the siege against Kanbara castle in Suruga province, which was held by a garrison of 1000 men under the command of Hōjō Genan's son, Hōjō Ujinobu.
Takeda Katsuyori, the successor to Takeda Shingen’s leadership, initiated a siege on Kanbara castle in Suruga province. The fortress was defended by 1000 soldiers under the command of Hōjō Genan's son, Hōjō Ujinobu.