Mina wants to change and be a better person and she told herself, no one is going to get in her way of her becoming a better person. 

   Jinyoung came into her life, wanting to make her everyday difficult for her since she made his best friend's life hell. This is the lesson she deserves.

Mina is a girl who came to realization she needed to change herself for the better after she learned that she made her boyfriend’s life a living hell. Their break up opened up a light that showed her mistakes. Now she wants to better herself and earn forgiveness though a challenge now is thrown at her. Her ex-boyfriend’s best friend has his own plans. Jinyong hated seeing what his best friend went through and being the best friend he is, he said to Jaebum "Don't worry, I will teach her a lesson for you."