September 2023 marks the 100th commemoration of the 1923 Great Kanto Earthquake, which caused catastrophic damages to the southern part of the Tokyo metropolitan area. Since then, Tokyo has undergone major changes over the past 100 years, experiencing with the Tokyo Air Raid in 1945 and the postwar economic recovery. Regarding expansion of Tokyo Metropolitan Area, Murao et al. (2023) clarified that (1) the total number of houses increased, (2) although the number of wooden houses decreased to about 70%, the number of non-wooden houses increased 4 times in Tokyo, and (3) the relationship between regional vulnerability and building increase/decrease conditions. Following the analysis, this study examines the vertical urban development of Tokyo in view of urban risk in the 21^st century.