I'm gonna be honest. It was a background noise kinda watch, I couldn't care about the story, and I "watched" the past life plot on 1,5x speed while sleeping. If I would review the story only it's a 4 at most.
BUT. The leads, and especially Rowoon, were so incredible and funny that they convinced me to binge this. It was my first Rowoon drama and I was really surprised about his comedic timing. (I usually have a little prejudice about idol-actors for being casted only/mostly for looks, but OMG this guy is really a very TALENTED actor.)

I think I'm going to rewatch this but only the couple/cute scenes. It's the only interesting part but it's really worth the struggle.