By Chris Hogg
BBC correspondent in Tokyo
There is now a greater proportion of elderly people in Japan than anywhere else in the world, according to the country's government.
Japan is looking at incentives for people to have more children
Preliminary figures from last year's Japanese census show that the number of people aged 65 and over reached 21%, overtaking Italy for the first time.
The ratio of children under 15 is also lower than anywhere else in the world.
New ideas will be needed if Japan is to stem or even reverse what has become a worrying trend.
Japan keeps breaking records, but for all the wrong reasons. These latest figures provide more evidence of the difficulties the country faces.
Japan now has a greater proportion of older people than anywhere else on the planet - almost 27 million of them.
More than four million live alone, a greater number than at any time since the census began in 1920.
Throughout Japanese society, fewer and fewer people are finding partners.
Roughly three out of five women in their late twenties are unmarried, and a third of those in their early thirties.
Almost half the men in the same age group have not found a wife.
For both men and women in their twenties and thirties, the number who are unmarried has risen by about 5% since the last census five years ago.
So unsurprisingly, Japan's population is shrinking now.
The proportion of children is now smaller than anywhere else too.
The government has begun a new project to provide more childcare and to encourage fathers to take paternity leave.
Matchmaking services have even been launched by local councils to try to help people to marry.