I just finished watching this drama and I have to agree with many others that the second half was a bit disappointing. The climax felt like lazy writing and if I hadn't watched it all in one go, I don't think I would have been able to finish it.
However, I did love the OST. It had a heartwarming quality to it. The chemistry between the lead actors was okay, not great but not terrible either.
The memory loss of the female lead at the end was a bit sad but, I don't think she could have lived a normal life if she remembered all of her painful past. I do wish she could remember her 19th life at least.
Overall, the drama was decent, featuring a fantastic concept, but unfortunately, it fell short in its execution and storyline.