It doesn't utilize its 20 episodes length in a constructive way for a relationship driven drama. There's a huge dent of inconsistency in the writing, sometime it's coherent and well thought out and other times it's as if it was written by someone who just started using a keyboard. A lot of things change and progress in the background without showing or reasoning with it and we are left to accept them and fill the gaps ourselves. For example, how the characters' relationships to one another turned out in the last 2 episodes. Anyway, the drama ended up feeling incomplete in many ways.