Attitudinal data are commonly used to measure values, which in turn represent moral doctrines that are resistant to change and are the foundation for societal norms. This article examines changes in the attitudinal climate in Japan. Three national surveys (1994, 2000, and 2009) are used to examine a range of attitudes that measure a) the centrality of marriage and childbearing, b) nontraditional family behaviors, and c) gender roles in the work and family spheres. There is strong evidence of movement toward less-traditional attitudes during 1994-2000, followed by limited change in the 2000s. Period factors were paramount in the 1990s. Across the board, women hold less-traditional attitudes than men, and this difference has increased over time. Both engaging in nontraditional family behaviors (being married but remaining childless) and knowing someone who has engaged in nontraditional family behaviors (cohabitation) causally lead to holding nontraditional attitudes, suggesting mechanisms whereby changes in individual behavior can lead to changes in societal values.