The Katsura Family’s Daily Sex Life

Did he knock up the daughter, Miharu?

This one really has a unique angle, i.e. the mother being complicit in the cuckolding of her daughter's boyfriend and eventual fiancé. What makes it even better is that it was her actions in the beginning which caused her daughter to become adulterous. And to add insult to all that injury, she at least has enough respect for her husband to not bear another man's offspring, but obviously has no intention of preventing that fate from befalling the boyfriend.