When the Imagawa fell into disarray after their defeat at Battle of Okehazama, she turned against them and became leader of the Iio clan after Tsuratatsu's death.

The results of Okehazama had left the lords of Totomi Province in a chaotic state with Imagawa Yoshimoto's death.

Otazu no Kata learned of the tension between Imagawa-Ii-Iio and invited Naohira to a meeting with her husband and planned to eradicate it to claim prominence in Totomi.

She was outraged that her gender had considered her weak in the political field, so she strengthened the castle's defenses and sent an appeal to defect to the Takeda clan.

None who live here would dare submit their home to their enemy.On the first day of the siege, Sakai Tadatsugu and Ishikawa Kazumasa lost against the Otazu's army.

On the last day of the siege, Otatsu opened the gate and donned armor and fought with a naginata while she was accompanied by 18 armed women.

[2]For her heroic deed as a samurai woman, Ieyasu said of her in her memory: There is no man alive who could have protected their beliefs so rigidly like you did.According to Edo folklore, Otazu no kata became posthumously associated with the name Tsubakihime (椿姫, "Camellia Maiden"), because her grave and those of her maids blossomed with Japanese camellias.