He specializes in the sociological study of gender and family issues, in particular, the sexual division of labor and economic outcomes of divorce in Japan. Most recently, his research interests have included population policy and political discourses on medicine, biology, and demographic determinants of declining fertility. He is the editor of a book, A Quantitative Picture of Contemporary Japanese Families: Tradition and Modernity in the 21st Century (Tohoku University Press, 2013).