One of the biggest challenges for a local government with a declining population and shrinking tax base is to lure young families to move into their communities.

Tokyo's Edogawa Ward is one success story. About 37,000 people are moving to the ward annually, with 90 percent of them in their 20s and 30s.

The annual birthrate in Edogawa is close to 1 percent -- 7,000 babies in a population of 650,000 -- which is exceptionally high among the capital's 23 wards.