As the Japan Times says, 5% of all marriages in Japan are now international,
while 1.4% of Japan's population is non-Japanese:

http://www.japantimes.co.jp/cgi-bin/getarticle.pl5?nn20040208a3.htm

This doesn't count the numbers of Japanese women who move out of Japan and
marry elsewhere.

At what point will the numbers of mixed or emigrant Japanese outnumber
"pure" Japanese?  When today's young Japanese die, will their graves be
placed on top of department store roofs, next to blinking neon lights?  Will
foreign children playing tag knock over the gravestones?
In the future, will Buddha statues in Japan have pierced noses and afro
hair? Maybe pure Japanese will live only on isolated islands, where
pot-bellied babies have flies buzzing around their eyes.