Bad Guy (2010)

Both dramas are about getting revenge. Both are sad but the drama Bad Guy focuses on taking revenge. Watch it and you will not be dissapointed

about vengance and family and how you re own family can hurt you without any clear reasons

Love in Sadness music vibe is present in Bad Guy (and vice versa).
Melodramas with some suspense.
A fight with those in power. And falling in love during the fight.
Hidden identities. Lies. Pitiful.
Love in sadness is less painful, however.
Bad Guy is way more intense.

Both dramas involve a family secret and a crime investigation. Both male leads have grown up as orphans and experienced difficult childhoods. They are both seen as weird and off-putting by others and the FL's are the only ones that understand their true personalities. Jung So Min also stars in both dramas!