The National Survey on Family in Japan (NSFJ) is an official country-wide survey by the National Institute of Population and Social Security Research. Initiated in 1993, this cross-sectional survey repeats approximately every 5 years, with the most recent (7th) in 2022. Although it is an official government statistic under the Statistics Act, the survey also functions as a family study, continuously gathering data on spousal division of housework and childcare, support resources within and outside the family, intergenerational support relationships, and attitudes toward family. The special issue will share secondary analyses of NSFJ individual data (collected over more than 25 years) with members of this academic society. This introductory article (1) overviews the NSFJ, (2) discusses its differences and similarities with the National Family Research of Japan (NFRJ—a research project of the Japan Society of Family Sociology) and (3) explains the special issue’s background and objectives.

This paper examines how grandparents’ prior experiences of receiving support influence their provision of childcare support to their adult children. Drawing on data from the National Survey on Family in Japan conducted by the National Institute of Population and Social Security Research in 2013 and 2018, the analysis targets individuals with children aged 18 or older and who have grandchildren. The findings indicate that (1) experiences of receiving financial support is associated with an increased likelihood of providing financial assistance related to grandchildren (2013); and (2) experiences of receiving caregiving support is linked to greater provision of hands-on care for grandchildren (2018).These results suggest that childcare support from grandparents to their adult children is not solely a response to the needs of the parents. Instead, such support may reflect earlier experiences, thereby transmitting childcare support practices across generations.

In Japanese society, where population aging and declining birthrates have resulted in extended parent–child relationships and fewer siblings, intergenerational financial support has become a significant aspect of daily life. This study investigates the relationship between intergenerational economic assistance and factors such as sibling count, birth order, and gender, using data from the National Survey on Family in Japan. The analysis indicates that a greater number of siblings in the younger generation is associated with reduced economic assistance from parents to children. Conversely, regarding assistance from children to parents, later birth order correlates with lower levels of support. Additionally, gender-based differences were observed: sons were found to receive more financial support from parents than daughters. Although financial assistance may be driven by immediate life needs, sibling composition also influences these patterns. These findings suggest that generational perceptions and lived experiences within families play a role in shaping economic support relationships between parents and children.

This study examines the evolving dynamics of socialization, re-familialization, individualization, and marketization of eldercare in post–Long-Term Care Insurance (LTCI) Japan. The analysis focuses on two dimensions: the allocation of primary caregiving roles within families and the utilization of institutional care services. Using data from the National Survey on Family in Japan (2003–2018), we analyzed dyads of elderly parents and parents-in-law requiring care, estimating logistic regression models for each survey year to compare changes in coefficients over time. The results revealed that, regarding primary caregiver roles, differences based on employment status have narrowed, while the association between parent–child relationship intimacy (measured by kinship type and knowledge of parental education as a proxy for relationship closeness) and caregiving responsibility has strengthened. With respect to institutional care, utilization was more likely when parent–child relationships were distant and less likely when the elderly parent had a surviving spouse. These findings indicate that family caregiving practices continue to undergo complex transformations under the LTCI system.