The recent emergence of the novel phenomenon of Japanese grandfathers' involvement in caring for grandchildren, especially their daughters' children, invites the question of how grandchild care practices contribute to their happiness in retirement. In the context of a novel family relationship, grandfathers need to establish their role in grandchild care. Grandfathers perform select grandchild care activities and leverage their resources to cultivate emotional relationships across the extended family, particularly through acts of gift giving with their married daughters. Commensality is one example of a practice that illustrates the role of gifts in family relationships. Grandfathers protect their sense of masculinity by limiting their involvement, for example by declining to change diapers or cook children's meals – activities at which they may be capable, but still consider to be inconsistent with male norms. This reaffirmation of their sense of masculinity provides emotional stability, and thus a foundation for their well-being.