Bit of a mystery why we're focusing on Japan. Global fertility is below replacement rate [0]. China and South Korea seem to be more extreme cases.
We seem to have stumbled over the solution to overpopulation. Wealth. Not many people saw that coming. In some ways, this is the best possible outcome as it beats war, famine, plague and dealing with the tax office as ways to conclude the story of civilisations.
EDIT And obviously I'm exaggerating. There are a bunch of countries still having lots of kids; but this is hardly a Japanese phenomenon.
We seem to have stumbled over the solution to overpopulation. Wealth. Not many people saw that coming. In some ways, this is the best possible outcome as it beats war, famine, plague and dealing with the tax office as ways to conclude the story of civilisations.
EDIT And obviously I'm exaggerating. There are a bunch of countries still having lots of kids; but this is hardly a Japanese phenomenon.
[0] https://en.wikipedia.org/wiki/Total_fertility_rate