Its a typical plot with a few different twists in how characters are presented and yes there are double couples in this drama but i was put off with the male lead always seeming to always be saving a damsel in distress with the female lead. I prefer the second leads romance towards the end cos it did drag out in the last few episodes. The development of the male couples relationship and how much the male lead cares for her seems to be what the drama is worth watching for.
Overall its a good drama but didnt need to have a long ending, personally think it couldve ended at episode 18 or something.