I usually have pretty low expectations for a rom-com with a mostly unknown cast, so the bar was pretty low for this. It was better than expected, but even so I nearly dropped it at around ep. 8 - the only reason I finished it was that it would be over in 12 episodes. And, also, I was bored. :(
The biggest problem was pacing. There was far too much time spent on persecuting the chicken restaurant owner, a nice guy although really a bit simple and too trusting. The plot finally expanded far into it, but as interesting plot lines developed, it was over. As a result, the whole thing wrapped up in a big hurry in the 12th episode, although to do the sub-plots justice it needed several more episodes. A typically rushed K-drama ending. The character development was simplistic and shallow. The plot had promise but the whole show felt like a throwaway that everyone had lost interest in by the end.
The music was really annoying. A couple of songs have been lifted from Boys before Flowers, and it was jarring to have them inserted here - one minute I was in a chicken restaurant, and the next I was back in time with images on Kim Hyun Joong and the rest of the cast, going to a snobby private school. I should have just watched BBF again!
The acting wasn't terrible, given the material they had to work with.
Don't waste your time here unless you are in the middle of a K-drama drought.