Dating and marriage in japan
I guess that if the average Japanese man loses interest in his wife once she becomes a mother, there is no problem with children either.
The typical reaction of Westerners is that they would be afraid of crushing their new-born baby by sleeping in the same bed, but it apparently never happens in reality (of all mammals, only male sealions and pandas sometime crush their babies to death when sleeping with them, but never humans, it would seem).
Without starting a debate on the merits on individualistic vs collectvistic cultures, one obvious negative aspect of collectvism is that it discourages to think critically by themselves - a serious issue for Japanese educators.
Even in love marriages, once a woman has a baby, her husband regards her as a mother, not a woman anymore, which means their sexual life typically comes to an end.
The new mother is said to lose completely interest in her husband anyway (this may not be true for international couples, from what I have heard).
For international couples who do continue to have an active sexual life, I was told little babies can sleep very well even with the parents doing whatever they please right beside them.
But they should have their own room from the age of 3 or 4 then.