All I can say is - everything can happen. A well written drama with toned down characters. It wasn't over dramatic and they showed the real university life and the hardships behind it.
Over the episodes you really get to know the characters and realize that nobody is perfect here. Everybody has some baggage that comes in and disturbs the present.
All of your favourites will be challenged in here so be warned! Watch this with no expectations. It's a really good trip to take in the dramaland!
This of it as the Korean 'Game of Thrones'! :)