ABSTRACT
This chapter explores the role that the koseki and juminhyo play in producing and perpetuating particular notions of family, gender and identity that Tanaka Sumiko and Fukukita Noboru have helped expose by refusing to register their relationship as a marriage. Tanaka and Fukukita's decades-long activism suggests the entanglement of social norms, legal contradictions and the continued domination of a particular heteronormative family structure embedded in the koseki document itself. A number of lawsuits claiming discrimination against women because of the single surname requirement in the koseki are currently before the courts. The postwar period was marked by the emergence of a new configuration for the middle-class family, characterized in urban areas by the pairing of a 'company man' and a 'professional housewife'. It shows that the registration system is deeply entangled with attitudes about gender rooted in a particular ie/koseki-centered heteronormativity that continues to influence laws, social norms, and attitudes about marriage and identity.
