The Tokyo region experienced massive growth during the twentieth century, and Okata and Murayama explore some of the consequences of rapid expansion without strong planning. The Tokyo Metropolitan Government did not enact strong planning laws until the 1960's, and even afterward development was haphazard and very often under served by urban infrastructure. It's important to recall that while sprawl poses a large problem for Tokyo, the framework of sprawl used by North American planners should not be employed.
Most new construction was transit-oriented development - Tokyo's new suburbs were largely not populated by automobile commuters. And unlike the United States, Tokyo (and Japan overall) is currently undergoing a rapid retraction as the population begins to shrink and younger people move closer to the inner city. This puts pressure on the older single family homes in the inner wards to develop high-rise manshons which strain the already thin layer of infrastructure and open space of the neighborhood.
This type of vertical sprawl (for lack of a better term) appeared to pose a significant issue for inner-city Tokyo residents, as neighborhood groups found themselves ill-equipped to take on the real-estate industry. Battles over new developments go beyond simple NIMBY-ism, as lax planning laws and recent deregulation allowed for construction that was not only out of scale, but which would definitively change the neighborhood's population and living conditions. This, at least, seemed clear from Fuji, Okata, and Sorenson's study.
While these new high-rise developments are disruptive, it appears that the problem stems from these issues of lax planning in the past. It is because development occurs lot-by-lot and that new neighborhoods were built almost informally that we see these conflicts today. It is because neighborhoods are so under served by open space and other community facilities that an influx of young residents may be a concern.
I liked Okata and Murayama's conclusion to their work:
Mixed use and vibrant looking vernacular urban places, often praised by European and American planners and urban designers, are merely incidental results of market economy and loose land use/building regulations and are actually vulnerable in many ways.
So while the Tokyo Metropolitan Government appears to be ahead of the national government in planning issues, neighborhoods in Tokyo will continue to be subject to the whims of the real estate industry. I'll try to suppress my own USA-centric understandings of planning while I'm in Tokyo, but these readings gave me the impression that planning as a profession has its work cut out for it in Japan.