Demographics in Tokyo between 1920 and 1965 could not be clarified because of a severe social crisis resulting from two significant disasters—the Great Tokyo Earthquake and the Great Tokyo Air Raid—as well as by subsequent land re-zoning projects and residential address reorganization policies, such as Chomei Chiban Seiri and Jyukyo Hyoji. This missing period is addressed by scrutinizing comparability between cho-scale tabulations of different censuses carried out in this timeframe and visualizing changes in comparable districts. The findings are summarized as follows.
(1) Areas within about 5 km from central Tokyo, which could be covered by foot, were already fully urbanized by 1908. Areas more than 5 km from central Tokyo became urbanized with the development of streetcar lines after the 1910s.
(2) There were only small differences in the socio-spatial structure between areas within 5 km of central Tokyo in 1920 and those in 1965. Nevertheless, small and medium-size factory and blue-collar areas in the western valley region diverged. Although northwestern valley areas continued to have a predominant demography of laborers working in small and medium-sized factories, they rapidly disappeared in southwestern valley areas. The main reason for this contrast is that the former continued to be competitive in the core industry of printing and publishing.
(3) In contrast to concentric spatial patterns of familial characteristics after the 1970s, those in 1920 showed clear distinctions between outer-eastern and outer-western Tokyo. This change was led by a labor force recomposition of the former after WWII. Before the war, outer-eastern Tokyo was made up of industrial areas whose labor forces were occupied by middle-aged workers with families and children. After the war, its core labor force was replaced by young singles moving in from surrounding and non-metropolitan areas.