It makes me wonder if their places were switched, how would kouhai treat her? I genuinely think kouhai is into both of them and she doesn't want to be left behind.
Despite everything going on, Maseki seems pretty down with whatever class reps got going on. She's probably one of the few people who would listen and believe the class rep.
So shark girl is just the ultimate wing man eh? I guess she doesn't really have any romantic feelings but gets a kick out of this whole ordeal and enjoys being involved