✔ 最佳答案
There are several version in infidelity as concept. Just generally speaking imo to Japanese married couples as below.
Because Japan is not Christian religious oriented country and the affair itself doesn't mean any illegality without any civil action, it seems that it is pretty difficult to figure the real scores in Japan.
Furthemore, Buddhism is quite generous to indifidelity so some extent too. I mean even it is prohibited to do just fun inconstantly to anybody, Buddha allowed people to do even if they have really love(or mercy) to do so.
It seems that is quite sensitive and unique morality and ethical flexiibility. I don't know if still Japanese are mainly influenced by this kind of religious concept or not though but it seems somehow still it remains anyway.
Of course, both Shintoism and Buddhism warn to keep moderation in life but there is no heavy penalty to infidelity itself. I think those religion might take more significant priority to some other principles to advocate its religious justification for people.
Adultery is not so uncommon in Japan and at the same time, there is still sort of conservative mind as man should be unfaithful naturally as far as he is still stud if he is so vigorous to well enough dominate and manage over the family in elder generation there in Japan.
The younger generation on the contrary looks so much more faithful to each other along with the spirit of the equality of mutual sexes. Or otherwise, woman may become to be more unfaithful equally in a degree.
However, it seems Japanese wives don't want to sleep with different man from his husband often rather than some other Western countries ones. That is why In Japanese there is no one-word to the meaning of cuckold actually.