They weren't blood-related, but Jiyong thought of her as his little sister. He wanted to protect her and help her throughout her problems but somehow things escalated in a different direction. He was getting possessive and protective which wasn't like a brother would for his sister.  Dara on other hand had always had a little crush on him but never realized until her friend showed some interest in pursuing him. she was jealous. 

Kang Seulgi a broke college student with very cliche abusive parents met the leader of a very dangerous   Loan Shark Group called the "Red Velvet"   Bae Joohyun Who also goes by the name of Irene.   Was nothing more of a bored woman sick of having greedy people begging to be loaned but when the time for them to pay back they just dissapear.     It just happens that the Kang Family was one of those people and it is