In the first month of the twelfth year of Bun’ei (1275), Nichigen-nyo, the wife of Shijō Kingo, informed Nichiren Daishonin that she had turned p.465thirty-three, an age thought to be unlucky for women, and sent offerings. This letter, dated the twenty-seventh day of the same month, is the Daishonin’s reply. In response to Nichigen-nyo’s apprehensions, he assures her that a woman who embraces the Lotus Sutra surpasses all other people, and that, if her faith is strong, she will certainly be protected by the Buddhas and Buddhist gods.

The Daishonin praises Shijō Kingo as foremost among all Buddhist lay believers; as his wife, Nichigen-nyo is also foremost among the women in Japan. “The wisteria depends on the pine tree, and a woman depends on a man” reflects the structure of Japanese society in the medieval period, when a woman’s fortunes were largely determined by her husband. What the Daishonin urges here, however, is that Nichigen-nyo follow her husband in faith. This shared faith of husband and wife is the “unity” referred to in this letter’s title and forms the ideal basis of marriage.

https://www.nichirenlibrary.org/en/wnd-1/Content/54