He's the kind of friend that says he wants to punch you, but won't. Me, I'd go back to class, and in front of everyone explain how all the girls hanging with Kotaro are hot for him and watch the chaos that ensues while literally everyone agrees except the girls that will immediately deny...
Thus is the fate of all (or nearly all) light novel and web novel adaptations. Promotional material to boost sales of the original work and nothing more.