This might be the best drama I have watched in the last year. Everything about this drama was perfect.

The OST is wonderful (there is one song that I keep playing on repeat since watching this). Every single song matched the mood perfectly and highly contributed to the overall experience.

The acting was out of this world, all of the characters did amazing, but I really liked Greg Han and how he was able to convey the different people and different ages and levels of maturity, it was absolutely wonderful.

The story has so much depth, so many plot twists, it honestly had you on the tip of your toes the whole time. Once I started it I was unable to put it down. I had to know what happened next. I tend to accurately guess how most dramas are going to end and the developments that will happen, but this one kept me guessing which was absolutely amazing.

The side characters are wonderful and it is great to see how they change and develop as the story goes. The "world" is really well constructed. You get to experience how things were back then as the story moves to the past, which was a bit reminiscent of the Reply series.

This drama is a wonderful slice of life mixed in with time travel and a murder mystery. All in all I am extremely surprised that is is not more popular than it is since it might be one of the best things to come out recently.