In this world, everyone has a first gender (Male, Female, Intersex, Non-binary, etc.), but at sixteen, sometimes earlier at fifteen or later at seventeen or eighteen, but uncommonly, everyone gets a secondary gender (Omega, Alpha, or Beta), which the secondary genders will give someone certain instincts that apply to that gender, but they can still have traits of any other secondary gender, which is how you might find more obedient Alpha's or Boisterous Omega's. Everyone is required to wear scent patches to cover their scent glands until they reach adulthood, and then they have the option of wearing them. Omega's specifically need to wear collars on top of scent patches to keep others from marking their necks during intercourse when marking is not desired.

The class is staying in the dorms for the day, and each of them is doing their own thing, Kirishima, Sero, and Kaminari are playing a video game, Mina is painting Shoto's nails, Bakugo, Izuku, Toru, Momo, Jirou, Shouji, and Mineta are all in their rooms, Iida is sitting on the couch watching them all while also reading to himself, Sato is in the kitchen, then Uraraka is putting together a puzzle.

Kaminari: "Dang! How are you so good at this?!"

Sero: "Maybe you just suck."

Kirishima: "Oh come on, that wasn't very manly, Sero, he just needs to work on his techniques, then I'm sure he'll know better-"

Izuku comes out of the elevator, Katsuki right behind him.

Izuku: "Oh, hey guys, what are you all doing down here?"