I love Netflix because sometimes it offers us really good shows like this one.
 Story: ok, it's not so original, even very foreseeable from time to time, but nice and funny. The only thing I wasn't really happy (overall in the last episode) was that for me, parts of the plot were too similar to Coffee Prince (and I loved this show, but I would have prefered something different).  
Acting: the gem of this show is the acting of the three main actors. I have already seen Park Bo Young in Strong Woman Do Bong Soon and I loved her, so I was happy to see her again doing two different roles, sooo funny when she acts as the ghost. I liked the fact that even having seen her in others films/series, it was easy to forget about it, so good was her acting.
Music: it's ok, nothing special, although the main song is nice to hear.
Rewatch value: perhaps some scenes or episodes. Not anytime soon.