This paper focuses on the redevelopment of the Kirigaoka Public housing in Tokyo. Kirigaoka Public housing is typical of danchi, the enormous complexes established in the 1960s, and more than half of its inhabitants today consist of the elderly. As such, it is thought of as a proper example to show the historical process of public housing policy and, also, the formation of the culture within it. This paper will focus on two points, in particular. First, as the danchi is redeveloped, the average size of the houses is getting smaller. Especially, ``1DK``(32㎡) units for single person household are planned to represent 40% of all units. This shows the current system of house welfare as well as the collapse of the modern family. Second, the redevelopment has broken and reshaped the elderly community. The examination associated with the redevelopment of the local community sheds light on the limits and possibilities of regional care for the elderly. This study aims to explore how public housing dynamically emerged from the modern super-aged society and, thereby, to discuss the formation of public housing focusing on the complicated mutual relationship of its residents, regions, and national policy. Furthermore, another objective of this study is to examine the possibility of regional care, specifically based on the elderly communities in public danchi. Understanding the process of social practice on public housing will provide us with clues to illuminate the bright and dark sides of the modern welfare state.