Yeah, but it is not acceptable to try to boost natality by denying opportunity to 50% of adults. My response would be "ok, you don't want me to be a productive

Yeah, but it is not acceptable to try to boost natality by denying opportunity to 50% of adults. My response would be "ok, you don't want me to be a productive member of the society in the way I wanted, I won't be in any other way whatsoever". OTOH I'd guess that low natality in Japan has other factors, as other comments pointed, even for men: long, long hours of work, living in a cage called "apartment", probably no leeway in the work to handle domestic problems (yes, even living under the most conservative marriage arrangement possible, there will be domestic emergencies all the time, where a man needs to step in).