But there isn't a major housing problem in the cities at all: there's lots of housing, and lots of new construction for new housing, keeping prices in check. The problem everywhere else is that people don't want to build housing, and that factor doesn't apply in Japan. Here, if you can buy the land, you can basically build whateverTF you want on it. So in desirable places, big real estate companies like Mitsui Fudosan buy up land and build apartment blocks or tower mansions on them, and in farther-out (less dense) places old houses are routinely demolished and replaced with new ones. There's no worry about NIMBYs keeping you from building.