I feel like the real problem here isn't just that prez is a morally bankrupt prankster... it's that someone was dangling funding for the clubs over these unathletic kids during a sports festival.
I fucking hate how she's getting jealous about senpai and his fucking COUSIN. I've always hated how family members are sometimes, for whatever fucking reason, part of the love triangle. It's stupid, and just weird. She is getting angry that senpai is even touching her in a non-sexual manner, during a fucking three-legged race. It's just weird.
Perspective: The previous prime minister of Japan (or the one before that, I don't keep track of when these guys change over there) was married to his cousin. That is not just a thing there legally (it's legal in a lot of places, you might not even realize it if it is legal where you are) it's a thing
socially. The reason nobody's marrying their cousins in a lot of the places it has always been legal is because it's still socially unacceptable.
Now, it's starting to be considered a little weird by the younger generation(s) in Japan, I think, but it was already a thing there. Which means it was a thing in manga, and it's continuing to be a thing in the medium because even the newer artists had read and enjoyed stories that had a cousin as a plausible romantic interest in love triangles and harems. I wouldn't expect an abrupt distancing from this in manga any time soon unless they actually change the laws there, first. They probably wouldn't take away the legality of this though, because they've got that whole declining birthrate thing going on. They want more people to have kids, if it's gotta be borderline flipper-babies, so be it.
You don't have to like that this is a thing in manga, but you should probably understand why it's there.