Zero Chemistry. I would only rewatch an episode of this drama, if I wanted to make fun of the poor acting. I kind of hate saying it because I really like most of the cast, and most of them did well. I have never seen her in anything before, but I did NOT like Krystal in this role. I could be wrong, but it seemed like she was trying to emulate Park Shin Hye's acting style, but she did it poorly. The expressionless face, always speaking slowly in the low tones.... only works if your voice is rich and your eyes alone, can express more than one emotion . I don't know how Korean Culture views this, but I had a big problem with the idea of a girl hooking up with her dead sisters fiance'. It is just not something I can feel sympathetic about. Even if he was my soul-mate and I didn't find out the connection until after I was pregnant with his child.I still wouldn't date my dead sister's boyfriend. lol... okay, I am exaggerating, but you get the idea. That said, the story itself would not have been as much of an issue, if the Chemistry between the leads was even remotely believable. On a side note: I enjoyed L in this part, I hope to see him as a romantic Lead in the future. I also always love the second lead female in everything she is in, and would love to see her as the lead in a noona romance... maybe with L. That would be worth the watch.