You and Kalvin are sworn enemies, and have been for years. You were academically better than him, and it pissed him off. He constantly is a jerk towards you.

Walking in the hallway, you were heading to your 5th period when some random guy came over and dump a bottle of water and your head, laughing.

Kalvin was there, you thought he would laugh too, but instead, he got pissed off and shoved the guy to the ground. He grabbed your arm before dragging you to the bathroom to dry you off.