It seems like a strange problem, but actually Japan is an aging country. The birth rate is falling, mostly because raising children in Japan is really expensive. So much importance is put on going to the finest schools, including cram schools and extra lessons, all the way up to college. Parents want to have just one or two children and pour all their resources into them. Some of my students work at a pharmaceutical company that initiated "Family Friday" a few months ago. Employees are encouraged to go home at 3:30 pm on Friday to, uh, "spend time" with their families (aka make babies).