She was one of modern Japan's most commercially successful and prolific writers, specializing in serialized romance novels and adolescent girls' fiction, as well as being a pioneer in Japanese lesbian literature, including the Class S genre.

[1][4] Her middle-class, culturally conservative parents trained her for the "good wife, wise mother" role expected of women in Meiji Japan.

In 1962, she built a traditional wooden house with Japanese-style garden in a quiet area, which she willed to the city of Kamakura on her death, to be used to promote women's cultural and educational activities.

Her house is now the Yoshiya Nobuko Memorial Museum, and preserves the study as she left it, with items such as handwritten manuscripts and favorite objects on display.

[10] In 1957, Yoshiya adopted Monma as her daughter, the only legal way for lesbians to share property and make medical decisions for each other at the time.

Her Chi no hate made ("To the Ends of the Earth", 1920), won a literary prize from The Asahi Shimbun, and reflects some Christian influence.

[12] After Black Rose, Yoshiya began presenting adult same-sex love as being akin to sisterhood and complementary to heterosexuality.

[15] Yoshiya's other major works include Onna no yujo ("Women's Friendship", 1933–1934), Otto no Teiso ( 良人の貞操 "A Husband's Chastity", 1936–1937), Onibi (鬼火 "Demon Fire", 1951), Atakake no hitobito ( 安宅家の人々 "The Ataka Family", 1964–1965), Tokugawa no fujintachi ( 徳川の夫人たち "Tokugawa Women", 1966), and Nyonin Heike ( 女人平家 "Ladies of the Heike", 1971) Her stories of dosei-ai (same-sex love) and of female friendships had a direct influence on later shōjo manga.

Her work in this period often has a sad and cruel ending, making extensive use of death from unrequited love or the double suicide of girls as a result of the threat of marriage to their relationship.

At the same time, although she continued to develop her sensual, nostalgic and emotional narrative style, the relationship between the heroines in her subsequent works began to be portrayed as more platonic, rather idealizing friendship and sisterhood between innocent girls, than any open or implied lesbian attachments.