My dissertation examines the emergence of kinship as a cultural, scientific and literary concept in late 19th and early 20th century Japan (1870-1930). It does this by examining works by two transnational Japanese literary writers-Natsume Soseki and Koizumi Yakumo (also known as Lafcadio Hearn)-for whom the concept of kinship was a central concern. As the borders of the Japanese empire expanded during the late 19th and early 20th century, the state increasingly drew upon the language of biological kinship in order to justify an imperial project rooted in ethnic nationalism. Drawing on a diverse array of material from evolutionary theory and eugenics, to colonial anthropology, ethnography, and composite photography, my dissertation shows how transnational Japanese writers used literary writing to forge alternative modes of affective belonging to construct a literary notion of kinship forged from the bonds between readers and writers, rather than through race or nationhood.