The purpose of this article is to show that the historical construction of the gendered division of labour was part of a genuine process of modernisation, that is to say, of the development of a social policy, as industrialism expanded, that would be compatible with a given political and social ideology and with objectives of economic development. What was called, after the war, the « Japanese style welfare society » (nihonteki fukushi shakai) by the Liberal Democratic Party in power was based, in a more democratic political context, on essential principles of social solidarity, based on the norm of the male breadwinner that had been developed in the framework of a « corporatist » project conceived before 1945.