ok so i got a nice scoop on a manga that should have lots of IB in the future and has already had some so far.
http://kissmanga.com/Manga/Re-Monster
this is re:Monster. the story is that a guy dies and is reborn as a goblin.
The IB comes to the plot in that as goblins gain power they evolve into more human, and usually better looking forms. While the main character is male there are 2 female goblins he is dragging up the ladder with him and one evolves in chapter 5.
It's a mild jump with some age up, but looking at the human females from the first chapter I would bet the girls will rival or surpass them in the beauty department before to long.