What exactly is the problem that you speak of, that a country that is massively over populated has a declining population?
The problem is that all those unmarried people aren't just going to disappear. They will age, and create a situation where the fewer and fewer young people have to manage a country that is increasingly dominated by the elderly. There is almost no way they will be able to support them all. Who will man the factories? Who will join the Self Defense Force? Who will keep the economy afloat? Because it certainly won't be millions of seniors!
And then, a few decades from now when they begin to die and the population crashes, and starts to shirk exponentially, what happens? The only comparable situation would be the Black Death in medieval Europe, but that society is nothing like modern Japan.
I think you are oversimplifying things.
That kind of stuff is a good start, but you shouldn't be making arguments based solely off stuff you've read or watched. That's just regurgitating the opinions you happen to agree with.
Stating the logical outcome of statistical analysis is not "regurgitating an opinion."
I was talking about your air of superiority about the state of America and how its system is so superior or even compatible with completely different cultures, all the while ignoring (or at least not stating) the other major problems we have as a country. We may not have the same population issue as Japan (although the U.S. fertility rate is on the decline like most other developed nations), we've got plenty of other issues to deal with.
We do have other issues. But those other issues are not a serious existential threat.
Japan has a lot of "firsts." It may not be pretty, but I can't see any scenario where it doesn't adapt. I honestly don't see how you seem to think they will just stop breeding completely at some point and the population will hit zero.
No one thinks the population will "hit zero." It isn't that simple. The problem isn't that they will "stop breeding" as you put it, but that their population growth becomes too low, or worse, negative. Our entire economic system right now is built on continuous growth, so unless Japan can engineer a way around this conundrum, there will be problems. You can't run a country largely populated by seniors.