三方原之戰
In 1572, Takeda Shingen personally invaded Iinoya and other castles in Totomi and Mikawa. The Battle of Mikatagahara took place near Naotora's domain. After days of resistance, Naotora surrendered Iinoya castle to the enemy to prevent bloodshed. In 1573, Shingen became sick and died in Naotora's domain. The Takeda clan army retreats from Iinoya and Naotora returned to being a daimyō. In 1582, she died of disease and was buried in the Ryōtan-ji temple. Naochika's son, the famed Ii Naomasa whom she adopted, succeeded her after her demise.