Due to her status as his concubine, her age when they met is not recorded but some historians postulate that she could have been in her early teens.

Her daughter Ichihime was promptly engaged to Date Masamune's heir, Toragikumaru, but died aged four after she ate some wild berries that poisoned her.

Because of this incident, Ieyasu ordered that 8 years old Tsuruchiyomaru (鶴千代丸) who was Kageyama-dono (Oman no Kata)'s child being adopted by Okaji.

Okaji was in low status, if she was killed or captured, it would not cause much turmoil in the Tokugawa clan, however, it is said that she served as an inspiration for Ieyasu.

She accompanied Ieyasu at the Battle of Sekigahara and the Siege of Osaka, dressed as a man she fought alongside other warriors.

It is speculated that she was a proud supporter of Lady Kasuga, the wet nurse and political advisor of Tokugawa Iemitsu.

After Ieyasu's death, there were few other noble women remaining in the Tokugawa clan, but there were still children who needed to be raised.