Hikaru is the richest and most handsome guy at school, so it's no wonder he's popular. After collapsing from a fever on his way home from school, he found something was VERY different about himself...
You know what this could actually make a very good manga the master got genderbent and he want his servant to have his way on to her doing everything the master wants to let his servant lay a hand on her lol.
The childhood flashback where he was in a dress.. Kinda wish they elaborated on that more than "Mom made me do it"; did she know he had the potential to swap genders for some reason? Was he originally a girl, and the male was the swapped form?
Yeah I'm confused by that ending. I kinda thought the butler installed false memories of her being male so she would be curious about having sex with him but I doubt that makes sense.