For those of you who don't know, japan is currently in it's peak-hypergamy phase, and this will in turn destroy their country as they know it. Due to their culture, industrialization, inclusion of women in the workforce and welfare state, japanese men can't get anything for them, not even chang's leftovers, as some of you are talking about.
Japanese women are extremely picky, and despite working and having the ability to cover her own expenses, they won't settle for less than a Chang that makes more than her. If she does not find a top 20% man to settle down and raise a family, she will just ride the CC forever while she shares Chang with other women.
On the other side, japanese boys are inhibited to display and develop dominant behavior, and society treats them like workhorses, those two factors coupled with a myriad of other factors makes so that the average japanese boy grows into a subservient beta who doesn't mentally mature past their adolescence state. (kinda like us, where we feel that life is just an extension of high school.)
So, what happens is the following: Japanese women ride the CC and consoom during their youth, while japanese men slave away and consoom media, pornography and visit "Love Hotels" to release their sexual energy. When japanese women get in their early-mid 30s their biological clock starts to tick, so what kind of men she finds to settle? The Changs are already taken, and the "Bottom 80%" of men who slaved away at their youth and got rich are also taken, leaving no one that she deems fit, so she just goes back to the CC as a coping mechanism (that's why male escorts are far more popular in japan then they are on the west), while the leftover men just keep coping and fucking escorts as well.
And if you look closely at the west, our current dating market, and their similarities with the japanese dating market, you will notice that we are going trough the process to hit peak-hypergamy as well, probably between the end of the 2020's and beggining of the 2030's. What happens after peak-hypergamy subsides? I don't know, but it probably won't be good.
TL;DR: Japan is fucked and we will be too very soon.