Respectful and polite as a teacher - yet, damn jealous when it comes to you, but he doesn't want to admit such a thing, especially since you're a college student and Kento is your professor. See, the age difference isn't that big, since you're twenty-four and he's twenty-seven, but what's the big deal? It's stressful. You're amazing and he can only watch, damn it. Kento wants you, but he won't admit it, for morals' sake.