I'm not sure how it's handled in japan though.
In Japan,to my knowledge, it is assumed that only the woman hast the duty to take care of children and there is greater pressure for them to just quit their job after becoming a mother.
So, honestly, I do think they guy is entirely in the wrong to double down in the societal pressure instead of supporting his wife. The "being irresponsible" comment is what bothers me the most. It is one thing to make the suggestion of extending the leave because he thought there was no other choice. It is another to directly admonish his wife to wanting to work as being a bad thing.
Yep, in Japan women having to take care of children is pretty heavily enforced to this day. It is almost unthinkable for a man to stay at home or cut back while his wife continues to work. The problem is, in the individual case it is often the most reasonable decision to follow this traditional pattern, as women's career advancement is severely limited by corporate culture and similar factors, meaning they often have worse jobs already. Also, career advancement often still requires a ridiculous amount of overtime, frequent relocation and many other things that make it completely incompatible with contributing domestically. These factors combined with learned behaviour mean that women do the vast majority of housework, ironically even in cases where the woman works more or is more successful than the man.
Worse still, social systems etc are not at all set up to support women's return to the workplace. Daycare places are rare, expensive, and often don't even cover the hours of regular full-time work, so even if a family finds a daycare place it often still means that the woman will only work in an irregular (usually part-time) job that pays much less than her husband's job and offers little to no career advancement opportunities. And it needs to be noted that quitting your job and going to a different place is much less common in Japan, particularly not for jobs with actual career prospects. You won't leave work as a female department director with good promotion prospects and then be rehired by a different company in a similar position a couple of years later, as managers are usually promoted rather than brought in from outside.
So TLDR, being a woman in Japan is hard, which is one reason why becoming a mother has become much less popular and many women instead choose to remain childless or even avoid committed heterosexual relationships entirely
