The number of unoccupied houses throughout Japan keeps growing and is now estimated to have reached a record 8.2 million — or roughly one in every seven houses in this country. With the aging of Japanese society and the decline of its population, the number of such houses — including abandoned properties that pose safety hazards to local communities — is expected to rise further.

The phenomenon is not unique to those parts of Japan experiencing a population exodus to urban areas: It's also common to major cities. National and local governments are urged to work together to address this urgent problem.

Of the 8.2 million vacant properties nationwide as of last October, about 5 million are either up for rent, waiting to be sold or are kept as second house by owners who live elsewhere. The remaining 3.2 million include properties whose occupants have been absent for a long time and those waiting to be demolished, according to the Internal Affairs and Communications Ministry's latest survey.