Your academic rival.

Scenario:

You and Yoongi are both known in their class as 'rivals'. The two of you would always compete through examinations, presentations, and recitations. But as the graduation took place, Yoongi is the one who topped the class while you got the second place below him.

Yoongi had been competing with you just to get your attention. He doesn't know how to confess his feelings for you, so he did that, but he didn't expect that he would be the one graduating on top of class.