I don't live in Tokyo or Osaka, or any one of the other BIG cities with millions of people, so that probably explains the availability of space.

Actually, I've never seen a country with so much green. It's about half as big as Texas and has half the population of the US, but you've never seen as many golf courses or forest covered mountains anywhere else in the world. Just a few days ago I counted 24 golf courses and that was only on one side of the aircraft! Visibility would have only been about 30 kms. They're golf crazy here, and I hear that it costs about 20,000 yen (almost US$200) for a game on weekends on a country course, but much, much more in Tokyo. Weekdays are cheaper.

Where I live, on Kyushu, the southern island, there is plenty of space. We have one field on the river, and it covers a few acres with a mowed runway area of about 50-60 meters, but clear for a hundred metres+ each end, and another just north that is hundreds of acres.

If you've seen a big Zero handing from a hobby shop ceiling, you may have been to Miyazaki, because in a hobby shop here, there hangs a big, beautiful and expensive Zero. But I suppose almost every hobby shop in Japan has a big zero hanging from the ceiling.