This started out very strong, made me cry multiple times during the first episodes - but late into the series it felt a bit draggy. There's many things that weren't relevant overall, had they cut it a bit and made it maybe 2 episodes shorter, it would have been perfect. The story felt very confusing at first, but once you settled it it was quite enjoyable. As for the acting, I was very disappointed in Kim So Hyun (Eun Bi/Eun Byul) - she was stiff and in my opinion didn't carry over emotions at all. Everyone else did a good job. The music ... I don't ever want to hear the 'Reset' song again, wasn't my cup of tea and I hit mute everytime it came up. I'd recommend this to people who like High School dramas, the mystery plot was too weak to be really important. Also, while this was a great first watch, I don't think it's something I'll touch again until many years later.