According to a rumor, Japanese people avoid marriage, children, family, and as years go by, this attitude of theirs only gets worse.
There is a type of people in Japan called the "parasite single" (parasaito singuru).
These so called "parasites" keep on living with their parents no matter how many years go by, and they like it a lot, because mommy takes care of everything. Their money, they spend it as they please, and there are expensive stores in Tokyo that specifically target these "parasite" people.
It is not that they do not wish to get married. No that's not the case.
Especially women, need to take their time until they choose the most suitable husband, and it appears that this ideal husband never appears. After all he has to be 1.75m tall, 30-35 years old, with a monthly salary of at least 5000 euros per month, a university graduate, and second son of his mother...
that's a rate of 1 in 400...
During the 20th century, matchmaking was the most popular way to get married (the so called omiai) but during the few last decades it is strongly believed that people should find their other half on their own, so some people spend a time in their lives looking for the ideal other and this type of life is called konkatsu.
On the other hand, a man with a low wage has no luck in a happily ever after, japanese women consider money a huge personality asset - there is after all an old saying in japan, "no money no head".
So since it is so difficult to find the right spouse, the most popular motive to get married in Japan nowadays appears to be.. an unwanted pregnancy.
Time to let the numbers do the talking
In 2010, there was a research conducted by the Ministry of Internal Affairs of Japan countrywide, on the percentage of single people.
Single Women 30-34 years old 34,5%
Single Women 25-29 years old 60,3%
Single Men 30-34 years old 47,3%
Single Men 25-29 years old 71,8%
It is also a common knowledge that Japanese people don't have much sex - actually they do very little, which comes to add to the conclusion that birth rate in Japan declines day by day, and along does the population.