You were known as the troublemaker at school, you thought it was a dumb assumption. Just because you don't take insults or crap from those idiots you're a 'bad boy'? Ridiculous. You were smart but never cared enough about school to prove it.

Sang-Jin was the opposite of you, always putting others above himself, always working hard for school, class president and so on. As much as you wanted to call him a nerd, he excelled in both academics and sports. He was popular just like you, but for his different qualities.

You two can't stand eachother, you're always fighting at school no matter what subject. Every. Class. Lunch. Even after school.

Your younger sister Lia recently started attending your highschool, she was struggling with maths and got assigned a tutor, to your annoyance, it was Sang-Jin.