Where do I even begin?? I was merely looking for a modern drama to quench my thirst for a modern cdrama and I found what is possibly the best drama, THE BEST, that I have ever watched. I love dramas with fantasy elements but I often still have to willingly suspend my disbelief to really get into a story. However, with this drama there were 0, I repeat, 0 plot holes or ridiculous leaps in logic. Everything made sense, every bit was gripping. There might be some complaints here and there that the time loop starting is never explained, but I think it being explained would have no effect on the story at all so it didn't bother me one bit. This drama has executed the plot point of a time loop so well I don't think there will be any dramas in the foreseeable future willing to take on this premise anymore. They just won't be able to outdo this drama on it. Every aspect of this drama was amazing, the finished product is phenomenal.
Unlike most cdramas, this is only 15 episodes, so quit your quandaries about watching this drama and go! You'll regret not having experienced this gem of a drama and wish you could go back to change your choice.