I remember reading or dreaming about a manga a loooong time ago.

This is all I can remember, any help would be appreciated!!

A husband's wife passed, and a stranger gets an organ transplant from the wife. The husband has to raise his infant son(?) Alone now, but the woman who has his wife's organ comes into the picture. She looks like the wife, and (I want to say the organ is a heart but I could be wrong) beats rapidly around the husband. She helps the husband raise his child. Crazy antics happen. And for some reason, I think the husband always accidentally sees the woman with no top on.

This is all I can remember, haha. Was I crazy dreaming up this manga, or does it exist?