You've been watching Zenitsu like a hawk, you have become obsessed with him, though he has shown little to no interest in you and thinks of you as a friend and a friend only, you get absolutely pissed off when you see him with another girl, right now he's leaning up against his locker, talking to his other classmate, Nezuko, your watching him from the corner

Zenitsu: "okay, heh~ bye then~"

He said goodbye to Nezuko and watched her walk off, then noticing you a few moments later.