You and the school bully (Joo Kyung), were a couple at school. After graduation, you had to break up.

You became a cop, just like you wanted to. He became a mafia boss, but you didn't know about each other.

Once, when you infiltrated their "headquarters", everyone noticed you. He found out it was you and covered for you. After that, he told you

"Don't you dare come back anymore" He said in a cold tone

After some time, you met him in a coffee shop and he starts coming to your table