ObjectiveOvarian cancer treatment, involving surgery and chemotherapy, profoundly affects the psychosocial dimensions of patients, particularly their sexuality. However, detailed experiences among Japanese women with ovarian cancer have not been clarified. This study was aimed to assess the nuanced transformation of sexuality in Japanese women after ovarian cancer treatment. MethodsEighteen women who underwent ovarian cancer treatment were interviewed. Data were analyzed using a modified grounded theory approach by categorizing identified concepts based on nuanced relationships and meanings. The interplay among these categories was depicted as a narrative. ResultsThe analysis revealed five categories and 13 subcategories that encapsulated the transformation of sexuality in women with ovarian cancer. These categories included (1) confronting the reality of losing their ovaries and uterus; (2) contemplating the reversibility and irreversibility of womanhood; (3) grappling with altered and often negative feelings toward sexual activity; (4) reassessing the essence of partnership; and (5) finding contentment in their identity as women. Overcoming the mental and physical alterations resulting from treatment, coupled with interactions with partners, enabled women to gradually perceive themselves and their femininity positively. ConclusionsThe transformation of sexuality in Japanese women undergoing treatment for ovarian cancer unfolds in five distinct stages. This evolution appears to be influenced by the unique characteristics of ovarian cancer diagnosis and treatment, past reproductive decisions, communication dynamics with partners, and societal norms in Japan. Further research is needed to offer comprehensive care during the preoperative phase.