So my head cannon is Shoto has horses.
Like if he gets stressed he will go ride a horse. He looks after them like they're his children.
Endeavor saw that Shoto liked horses and bought him some as a way to redeem himself and also to make Shoto happy after Deku cheated and they broke up.
So Shoto just disappears randomly to go see them.
Fuyumi and Natsuo like watching Shoto ride the horses and find it funny when one of them throw him off into mud.
Rei doesn't agree as she thinks horse riding and horses are a waste of time and Shoto should be training at UA.
Dabi told her to shut the fuck up and sometimes helps Shoto with the horses.
No one at UA knows about the horses.
A list of people who know
•The Todoroki's
•Eri
•Aizawa
•The LOV
•Hawks
•Overhaul