Manga by author Yoshihara Yuki - Status completed

From Viz:Choko Kuze is the sensible daughter of a venerable family who went bankrupt. She joins a real estate company as an entry-level office worker, but her eccentric boss is harder on her than anyone else in the company! After hearing him inadvertently call her "milady," she realizes he was the young servant boy she knew as a child. At work he's a tyrant, but after hours he insists on treating her like a lady of the nobility. Is romance even possible for a couple locked in such a crazy role reversal?

From MangaProject: Imagine what it is like to be raised by a gay father who insists that you call him "mom". The main character turns out to be a woman who doubts her sexual orientation, until she meets the right guy. She is so sure that he is "the one," that she goes out of her way to pursue him and then marries him lightning fast! Essentially, the rest of the story is about keeping the chemistry (a little twisted and crazy though).