Nothing much comes close to this masterpiece - within this genre.
Teisou Gyakuten Sekai (Chastity Reverse World) is nice and a fun read, but the art is much worse and it simply doesn't have the overall quality. The other gender ratio stories are way trashier, with worse art, etc. Some of them can be quite enjoyable too, but it's not even close in overall production values and consistency.
This manga so far has almost spotless writing and great art. Top notch.
Nah, Seira had very high special-prince standards all throughout, that's why she delayed pursuing just any guy... eventually realized the time is starting to run out (and everyone else has BF) and instantly agreed to date when some womanizer douchebag asked her out.