I was intrigued by the time travel premise and a few episodes in still held my interest. Around episode 8 I started to feel like Ji-won was getting a bit too thrilled with how well her plan was going even though she knew what kind of life Su-min would end up having to endure. However I still felt for Ji-won having to see after -10 years what her other half and her husband were really made of. Even so, I hope she changes her tact and saves Su-min from the life she once knew, even if they can never be friends again as she thought they once were.
Also I wager Yu-ra and Ji-won turn out to be sisters neither knew they ever had. They look so much alike, I wonder if Ji-hyuk's feelings toward Ji-won are subconsciously affected. It has only been about 16-17 years since Ji-won's mother left but what do we know of her 10+ years earlier than that? Could these two be maternal sisters? What about paternal? Could her mother have left after discovering her husband had another child with someone else? If I have learned anything of this show it is that the writers take advantage of the fact that anything can happen. Onward to S01E12...
P.S. Regarding the comments about the lead actress' physical appearance, weight loss, surgeries, etc., all I can see is that when she breaks out that smile, she goes from OK to super-beautiful in 0.00 seconds flat. Are there so many superficial people out there to care about the rest? And why? My guess is 90% of you never look in the mirror.