Since the late 2010s, the discussion regarding “women’s poverty” in Japan has focused on young, unmarried, and precariously employed women. There are some structural factors such as post-industrialization, inherent familialism in social policies, and problems related to sexual and reproductive health and rights (SRHR), that underlie the “new” difficulties faced by young women. Based on this social context, this study analysed the difficulties faced by single, non-regularly employed or unemployed women in Tokyo in terms of their work, family, economic situations, and health. Our analysis of data from an online survey of women aged 18–44 years in Tokyo yielded three findings. First, young single women living in Tokyo with non-regular employment or no employment had relatively adverse family backgrounds, education, and early careers. Moreover, they had negative experiences related to their health, school, and workplace. Second, they had various ongoing problems that differed from those of the other groups and were unlikely to consult anyone. Third, negative experiences related to school and family, work-related problems, and a lack of consultation were correlated with lower subjective well-being. In light of the aforementioned findings, the provision of effective support from national and local governments is crucial.