Same pattern in both series with the bodies swap between a younger and an older lady. "Otto no kanojo" seems like a remake except that the wife is mistaken that her husband is unfaithful when in fact he isn't. In the korean drama "Dorawayo Soon Ae-ssi" the husband is indeed cheating on his wife with a much younger colleague of his. There are quite some similarities in both dramas like the fact that the younger woman has quite some temper while the older one always try to put a good face, not causing any troubles and such. In the Korean drama they are rivals due to the circumstances.
