This is Yuna's side of the story
A few months had passed and Yeji hasn't told Haeji anything. Hyunjin asked me to help find Sana a gift for valentines day since he was obviously never breaking up with her. Only Yeji knew I liked Hyunjin and she usually comforts me when Sana is around.
Yuna: Hyunjinie Yeji is crying!
Hyunjin: OMG Yuna I'm coming. What happened?
Yeji: Haeji.. she was passed out on the street yesterday again and if I wasn't there she probably would be dead.
Sana: Uhm Yuna whatever your name is come here.
*Sana and Yuna in a different room*
Sana: So.. explain why your calling my boyfriend Hyunjinie? That's my nickname for him!
Yuna: He said I could call him that?
Sana: I'm sorry I just- don't want to be with another cheater..
Yuna: Huh? What happened tell me please!
Sana: It was.. four years ago. I was with a girl called Nayeon but she left me for someone.
Yuna: Who?
Sana: Some famous girl Kim Jennie. And she cheated on me in our relationship.
Yuna: I'm so sorry. Should we go back to Yeji? I'm really worried for her.
Sana: Sure let's go.