I got a link to this article from a friend of mine who lives in San Francisco (she's french)

http://sfgate.com/cgi-bin/article.cgi?file=pacnews/archive/2006/05/20/japanmoms20.DTL

Basically it's one reporter's view of why the birthrate in Japan is so low:

"Japan and Korea have a key cultural characteristic in common, according to the survey. The two Asian countries rely on the mother as the main caretaker, instead of viewing childrearing as a responsibility shared by both parents. About 68 percent of Japanese and Korean moms were the sole or main parent caring for a pre-K child, versus 36 percent of American moms.

In Japan, the nasty corporate practice of keeping workers late into the night is rampant. It's a habit that can be tracked back to the post-World War II days of economic development. If you have a job that has limited responsibilities, you might get off at a reasonable hour. But if your career is going anywhere, you're stuck at the office. "

And that's about it in a nutshell. When people ask me "how was Japan" when they find out I moved to Portland from Tokyo, there is so much that runs through my mind. The REAL answer to that question involves quite a complicated morass of emotions revolving around wife and childcare expectations in Japan, coupled by the far greater community and health support available there.

However, most of my Japanese wife friends were basically single moms. Everyone used to ooh and aah over how much Naoto was with the kids and how much he took care of them. More than one friend of mine commented that they hated the weekends (which I looked forward to as a rest) because their husbands got in the way and basically acted like another child.

So I agree with the reporter about the only way to "fix" the birthrate is by letting the work culture ease up a bit. However, it's not as simple as the article makes it out to be. Culturally Japanese women and men are used to having different spheres. It would take more than less working hours to fix that.