Problem:
Right now the harem page shows which girls are "Not recruited", but doesn't make it easy for you to see which ones are available right now.
Solution:
In addition to sorting the girls so that recruited girls are first, and "Not recruited" are last, have a middle group of "Not recruited -- AVAILABLE NOW", and highlight their slots / thumbnails a little (maybe with a diagonal stripe overlay that combines the looks of recruited and "Not recruited").