Sujin had to let go his first love for real and she wanted to move on from him but guess what.. After three years later, he's back but this time, would she have to take him back?

The World are always known for being big and scary. Seorin never thought one day, she will meet that one man for herself. She's not an assassin but when she needed to save her little brother, she can't help to make a use her pretty great combat skill and genius brain to let her brother free from the Mafia Lord. Seorin couldn't never expect she would find love at the most scariest place.

To be honest Luna like Seungwoo more but then she knows Seungwoo won't look at her way. Seungyoun was never in the picture until the two guy met and decided to be best friend. Seungyoun has his own way sometimes to show that he's interested in her. Seungwoo helps Seungyoun and that wasn't what Luna wants.