Yes, some similar and some distinct reasons for that, as I understand it. Like South Korea, Japan is a more westernized country. So they suffer from some of the same moral decay.

This combined with the honor culture and dissafected younger generations who believe they will never achieve what their parents did has led to a steep decline in marriage, childbearing, and economic productivity.

Adjascent to all that is the rapidly declining value of the yen.

I had a few years of a Japanese language class and have close friends of Japanese background so I've learned a bit about this country in particular among Asian nations, but I'm no expert. Those who have a better understanding of Japanese culture and economics can correct me if anything I said is off base.