Since the late 1990s, the population of Tokyo’s urban core has increasedtremendously. This study explores the local impact of resurgence on urbancore population growth, focusing on the renovation of the buildenvironmentsand the social composition of residents. We collecteddocuments of condominium developments and conducted a questionnairesurvey of urban residents from two districts in Tokyo, Nihonbashi-Tonyagai and Tsukishima of Chuo Ward. Both the districts have facedpopulation upsurges resulting from the rapid increase of building middleandhigh-rise blocks of flats, even though the nature of their experienceshas been different in three points: previous land use of condominiums,shifts in the social class of community residents, and social relationships.First, focusing on previous land use of condominiums, redevelopments inNihonbashi-Tonyagai fall under the concept of new-build gentrification(Davidson 2010) and those in Tsukishima can be interpreted partly asclassical gentrification and partly as new-build gentrification. Due to theshift in the industrial structure, some office buildings of wholesaling inNihonbashi-Tonyagai have changed into apartment buildings for highincomeindividuals. In Tsukishima, many apartment buildings haveredeveloped from office buildings, parking areas, and traditional row houses(nagaya) for the working class.Second, the two districts have experienced different changes in the socialcompositions of residents. In Nihonbashi-Tonyagai, new condominiumresidents have overwhelmed the longtime residents in number, which hasresulted in moderate social upgrading without direct populationdisplacement. Conversely, in Tsukishima, the influx of the young middleclasscaused social upgrading accompanied by the displacement of thelower class.Third, social connection among residents in Tsukishima is higher thanthat in Nihonbashi-Tonyagai, even though Tsukishima has also experiencedsharp gentrification. New condominium residents in Tsukishima haveactively participated in the local communities, while in Nihonbashi-Tonyagai, new and old residents are divided between their behavior andconsciousness.