I expect you'll find that most of us 'old gits' have built houses on property that was either our spouse's old family house, or on adjacent or nearby family-owned vacant land.
Certainly out here in the sticks, where you're much more likely to come across house-owning gaijin, a majority of the international couples build houses on family land - often disused farm land. And in fact we're only following a national trend by doing so. Fewer and fewer sons want to continue to grow rice and vegetables on the 'family land' once ojiisan dies. They'd much rather move out of their rabbit-hutches into nice modern houses and then sell the old house for firewood.
When I first started teaching some classes in my wife's family house there was a nearby collection of 12-15 rice fields there were farmed annually. Now, only two are used for rice. A couple more for vegetables and the rest are either fallow or had houses built upon them. Where there were no houses ten years ago there are now 15 all built separately and as far as I could make out by different firms.
Anyway, I'm wandering off-topic...first, most important thing is to have heaps of money to buy the land and being married to a 'solvent' Japanese national is almost a necessity. Don't forget that the 'bricks and mortar' are practically worthless once you take possession of the keys. Nobody buys houses in Japan - they buy land and build a house. Well, there IS house-buying but it's a very small market. Remember movement of labor in Japan is almost static. When father gets posted to Nagoya from Matumoto he moves into a 2DK near the office - his family will usually stay where they are! Lots of weekend papas in Japan - and their wives wouldn't have it any other way....
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