Uhm. I guess it's nice they are at least buying some hard-assets instead of government paper as far as the Yen is concerned, but someone ought to tell the peeps at the BoJ that if you have a stable, aging (and soon to be declining) population while you forbid foreigners from buying real-estate, chances are you are not going to have much luck supporting real-estate prices. Especially not when interest rates are already at record lows. It's that supply and demand thing you can learn from Mankiw's book.
Bank of Japan Pledges to Steadily Buy More Assets"...The BOJ’s purchases of real-estate investment trusts and exchange traded funds have bolstered stock prices, a sign the stimulus has supported sentiment even as global growth slows."
My suggestion? Start letting immigrants in. Seriously.