This article examines the historical trajectory of urban lower class society in modern Osaka. Taking into account developments from the early modern period, it analyzes the transformation, expansion, and structure of urban lower class society in the modern period, as well as the way of life of lower class city residents. Specifically, this article focuses on the example of the1930s. First, it analyzes urban lower class society, which was characterized in the early modern and modern periods by the fact that its members frequently gathered together in concentrated residential zones, while also considering the development of the city of Osaka as a whole. Centering on the transformation and dismantling of early modern Osaka's best-known slum district, Nagamachi, urban lower class society developed during the modern period in a form whereby new slums emerged during the processes of industrialization and urbanization. The slums that appeared after Nagamachi's dismantling, including Kamagasaki and those in the Nipponbashi neighborhood, each possessed a subtly different character. Entering the twentieth century, Osaka's slums became even more diverse. Not only did the city's largest outcas