Housing is pretty affordable in Japan since housing in Japan is not an investment, it depreciates like a car (only the land has value, the house ontop of it has literally negative value since it’s assumed anyone will want to bulldoze it), and their lax zoning allows for continual densification to happen.
You would assume that, but is it really true? The countries with the safest and most comfortable lives, in Scandinavia, have the lowest birth rates. The countries with the least safe and comfortable lives, in Africa, have the highest birth rates.