I don't think so at all. Growing outwards only works if you have an instantaneously fast transit system. There's a reason the real estate in central Tokyo is

I don't think so at all. Growing outwards only works if you have an instantaneously fast transit system. There's a reason the real estate in central Tokyo is some of the most valuable in the world: because it's close to everything. The farther out you go, the less valuable land is, because it takes time to get to the center (or anywhere else). This is of course true in American cities too, but zoning laws largely prevent new (and taller) housing construction close to the center, so they have no choice but to build outwards. In Japan, building upwards is much more feasible, only requiring that you acquire some desirable existing property first. (Of course, there are some limits to what you can build on it, but it's nothing like in the US so it's much easier to get approval to build some nicer and/or bigger/taller.)