@0181sam I believe that one reason for the declining population of Japan is their media depicts unhealthy relationships and very few actually show how to have a healthy one. If they were to have comics that had more realistic and healthy relationships it would be useful to educate the citizens of better ways to intermingle. They also have a bit of an issue with nationalism, but that is true for many countries these days.
From my knowledge in healthy relationships there is not an overwhelming sexual tension with a forced lack of sexual relations; thus not only making the stories like this unrealistic, but actually incorrectly educating citizens on how to actually have a prosperous relationship.