So, the MC is not interested in the boy that Girl Friend A has been drooling over. Turns out that he's not her type - which I was saying, and which her insensitive friend doesn't seem to grasp. So, rather than go with her friend to hang out in the dude's circle, for some reason the MC decides to go into the completely empty classroom.
(There's not a single person in there. Not one. Not an eager-to-please student who wants a good seat, or a loner student who hates the noisy hallway, or any other type of nerdy little student who's always early to class. Isn't that a little far-fetched?)
I thought she avoided empty rooms "at all cost"? Doesn't seem like much of a cost to hang with your "best friend" for another five minutes, even if she is just drooling over a boy who isn't your type. I mean, if you don't care one way or the other about the boy and you do get to hang out with your friend - whom I assume you pretend to feel affection for - then why is it worth it to risk going into an empty room?
Oh. Because the plot demands it. I understand. It doesn't have to make sense, it just has to happen.