Well I just finished watching 12 episodes and here I am commenting about what I like and dislike about this drama.

Story

Lets start with the story plot.The story plot itself is very interesting and cannot say like there is never been a drama like this but this theme(friendship between 2 female lead) is still not a common theme right now, So the plot itself is fresh and not boring.

Presentation
As we know beside story, the way the director present a drama also can be very important. Sometimes the plot can be the same but the presentation can be different.For this drama,I really like the presentation too.The director manage to present this drama in a mysterious way making this drama very attractive.

Acting skills
For the acting skills,Xu youyi's acting skills cannot say like extremely well or shines but its still passable considering the difficulty of this character is not low and the actor itself is not a very experienced actor. For yanwei, I really like this character but ya the difficulty for the character is slightly lower compare to xu youyi.

Music
I really love the songs in this drama including the ost and the other side songs.The songs are all very nice and fit to the mysterious theme of this drama.

Anything to improve?

First dislike is obviously the length of this drama,12 episodes is definitely not enough considering a lot of mysteries has not been solved.For example,yan wei"s background.And next is the you can feel that a lot of important scenes is cut off.I guess because this drama only 12 episodes so they cutted off a lot major scenes making you feel like did you just miss a few episodes?Really hope there will be a season 2 and the director can lengthen the drama a bit so that we won feel like scenes getting cut again.