Story: I have been watching lots of k dramas for 10 years now XD This story is quite unique, and the ending is quite unexpected (at least for me). Everything may seem weird and absurd in the beginnings, but it all makes sense toward the end when the friend group gets together. I think that many people felt underwhelmed with the ending cuz neither Won Tak nor Min Joo slept with anyone in their group. However, it makes sense because it suits the personality of their characters. Min Joo's disorder is a REAL disorder. It also goes by another name called sexsomnia. It is also better for them to not have anything with each other because they are FRIENDS. I would hate it if Won Tak had had an affair with his friend's wife or fiance. The drama explained why the two girls like Won Tak at the beginning and why the two guys yearn for Min Joo near the end. It is also understandable why WT looks for MJ at the end. All of this happened due to misunderstandings, so everyone was partly at fault. I don't know why some ppl say the ending predictable. I totally did not see that coming
Acting: The acting is very good. All of the cast is amazing. It is possible that ppl don't like the story cuz it is very different fr typical k dramas, but the excellent acting is sth that one cannot deny. If anyone thinks the acting in this drama is bad, then he/she is either an extremely experienced actor/actress or a hater. TMI, I am a musical theater major (junior yr), btw.
Music: I think the music used suits the mood of the drama