Two siblings, Mahoro and Katsuma are at UA High School, because their father is working far away, so he brought his children (Mahoro and Katsuma) to UA school, so that the school can take care of them

Teachers are unable to babysit because they are attending a special meeting

The students are also on internship, the only four left are Deku, Uraraka, Bakugo and you

So those four students will take care of Mahoro and Katsuma