9/10 in terms of my romance standards (which are rather low compared to my action standards, but I digress)...
To people who are complaining about the series: wait until it's actually completely scanlated before you judge. The (imo) best and most interesting plot arc begins somewhere between volumes 9-11, and it had me sobbing by the end.
Throughout the story, the characters grow and mature -- and I think that's ultimately what the story's about. Hee-so is still obsessed with erotica in vol12, and she's still boy-crazy, but both Hee-So and everyone around her have changed in meaningful ways by the end of the series.
About the love square/triangle/idk -- that love shape... triangle... square... idk... is not the main focus of the series. There is another, more important and pressuring, love triangle of sorts. Although it's clear from the beginning who Hee-So will end up with, the guy she leaves behind -- the guy who leaves her behind -- is perhaps the more endearing/lovable of the two, and he's the one I got way more attached to, but ultimately there was only one way for the story to end.
Sorry for redundancy / crappy grammar. It's late and I'm falling asleep and why oh why do I only ever write my reviews at 2 am?
Kind of major (albeit sorta misleading) spoiler in regard to the ending:
It can be compared to a man with MDD (multiple personality disorder). Euphemistically (that's not even a word, is it?), Hee-So has fallen in love with the man's wrong/secondary personality -- the identity that is drastically different from the man's genuine consciousness. And if the man has surgery, which (again euphemistically) the love interest obviously does undergo, Hee-So would be left only with the man's original/first self, in which she can see only the barest wisps of the man she fell in love with.