The rise of life expectancy throughout the developed world has meant that older adults play an increasingly important role in their grown-up children’s lives. We evaluate whether the intergenerational solidarity theory is useful for understanding the intergenerational transfers of time in Japan given the relatively generous welfare provision for the older adults and the fall in intergenerational coresidence. We apply seemingly unrelated regression models to data of the 2006 Japanese Survey on Time Use and Leisure Activities (Statistics Bureau Japan, 2006) to investigate how coresidence patterns are associated with paid and unpaid work time of adult married children. The sample contains 23,226 married couples where both husband and wife are aged 20 to 59. We find evidence of intergenerational solidarity in coresident households. We also find that “doing gender” is layered through intergenerational exchanges of support between married working-age children and their older parents. Working-age women’s time use patterns are associated with coresidence arrangements and care needs of their older relatives to a much greater extent than working-age men’s. The observed patterns are consistent with healthy older women supporting their daughters’ careers in exchange for care when they need help themselves. For working-age men, the patterns are not very pronounced. Notably, working-age husbands without children appear to be more responsive to their older the parents’ care needs, suggesting that fatherhood may be associated with solidifying gendered role performance within Japanese couples.