It's some sort of meditation on contemporary issues, school, family, expectations, love. There are also some funny moments and also very tragic ones. Even the main villain is not 100% pure evil so it puts everything in some sort of gray area.
The finale was really good in my opinion, there is some character development and that's what I appreciated the most.
The OST song is BEAUTIFUL I normally skip the first seconds of the beginning of a drama but I never ever skipped this song.
I will rewatch this drama for sure, especially because of the ending.