More than half of the empty houses, in fact, were acquired through inheritance, meaning they were supposed to be assets in the old days. But now many successors cannot utilize them because the houses are too old and low valued.

Houses would no longer be assets but debts in Japan. The cases that one cannot find buyers are commonplace. A $1,000 apartment in a ski resort--which used to be priced at hundreds of thousands dollars in the 1980s--became a topic recently on the Internet.

Besides the population decline, an oversupply of new homes backed by the people's preference tangles the situation further. Nomura Research Institute forecast that the empty house rate would increase to 30.2% by 2033.