With any luck at all, my field should hopefully be open (central Japan) by mid-summer. So many things to do, so many hoops to jump through.
There are a few (as in 4 or 5) non-military related paintball fields in Japan, and a few more if you count the wacky 11mm players (.68 caliber is 17mm.)
are sources for more information.
One of the key factors to the slow development of paintball in Japan is the lack of affordable suitable land. The country is essentially the size of California, 80% of that mountainous, with half the population of the entire USA. Do the math.