For once I really enjoyed following and watching a Korean drama. The story has nothing extraordinary and the characters are quite common but the actors are good and the direction is excellent. The scriptwriter had the intelligence to build a solid plot that does not evolve into unnecessarily complex events. But it is especially thanks to the direction that this series is of great quality. I have rarely seen a story so well filmed and edited. It was a real pleasure to watch some scenes. It happened several times to me to go back to see again certain sequences. Everything is excellent: the choice of shots, the lighting, the way of filming the places and the characters, the editing, etc.
We too often forget that a story, however good it may be on paper, will never make a good movie without a solid direction.
I have two criticisms to make. First of all, the music. It is sometimes too present and seems to underline too strongly the emotions of the characters. The other negative point concerns some lengths and some sequences are not really useful to the story. The last episode has a too predictable content. It was not necessary. This drama would be much better in 12 episodes.