Notice that all the people in these "apartments" are young. It's just the same old story of old people taking advantage of young people, and the young people aren't wise enough to understand how much they are getting screwed over.
Well a big chunk of Japanese teens seem to not be interested in sex.
The government's answer is always "increase the population" to keep the Ponzi scheme of the young providing for the old going on. Eventually, you can't increase the population any more and the whole thing falls apart.
Governments should look for ways to support retirees without requiring two working adults for every retiree. Geometric expansion is never sustainable.