Shinjou-no-tsubone was the daughter of Kumagai Nobunao. Mirage of Blaze gives her name as Lady Tomo, but her real name is unknown. She married Kikkawa Motoharu in 1547 and gave birth to Motoharu's eldest son Kikkawa Motonaga the following year, followed by Mouri Motouji and Kikkawa Hiroie. Although their marriage was a marriage of convenience, it was said Shinjou-no-tsubone and Motoharu grew to love each other deeply, and Motoharu never took a concubine.

In the Intoku Taihei Chronicles by Sen'a, a warrior and poet of the mid-Edo Era, Shinjou-no-tsubone is described as having a 'white, pockmarked head' who 'walked bowlegged with a hunched back.' He called her 'a woman of once-in-a-generation ugliness.'