After multiple months, she negotiated surrender and saved the lives of her men in return for agreeing to marry the attacking army's general.

Switching sides made her an enemy of Nobunaga, her nephew and head of the Oda clan, who eventually executed her along with her new husband and the castle's garrison.

Akiyama Nobutomo negotiated the castle's surrender with Lady Otsuya, and she settled in a peace treaty without bloodshed and ceased attacks.

The adopted son of Otsuya and the official keeper of the castle, a seven-year-old lord called Gobōmaru (Oda Katsunaga) was taken to the Takeda home in the province of Kai as a hostage.

[1] On April 12, 1573, Takeda Shingen died, and on December 22 of the same year, an event that led Lady Otsuya to lead the defense of Iwamura Castle once again.

[2] Representative from Ena City Board of Educational and Cultural Affairs Division has stated that Lady Otsuya has become a basis of popular legend as "female daimyo" who possessing "unmatched beauty."

However, this legend of a female castle lord has no historical sources and no basis, as it only appeared through anecdotes from the later era such as Kōyō Gunkan or ``Iwamura Fushi.