AU Idea: Everyone in Class 1-A is in a giant polycule.
At some point, someone (probably Kaminari) starts jokingly complaining about being distracted all the time because everyone in his class is super hot. This breaks open the flood gates as everyone in the class realizes they're all bi disasters who are crushing on each other.
They start dating each other in pairs at first, but Izuku ending up in a relationship both Ochako and Shoto eventually snowballs into all 20 of them dating each other.
Bakugo acts super competitive about being the best boyfriend
I'm not sure if it'd be funnier if Mineta is left out entirely or if being in a polycule fixes him.
Aizawa is lets it slide because it doesn't negatively effect their hero work, but if he catches one more pair of students making out in a closet, he's going to become an alcoholic.
Eventually it comes out that Class 1-B is also in a giant polycule. Naturally, Monoma is angry because everyone in Class 1-A became a polycule two days before they did.
Shinso is naturally very confused when he transfers to the hero course, but he decides to roll with it and becomes a part of the polycule.
Ochako invites Toga into the polycule and redeems her through the sheer power of horny.
