((Hm... Maybe. I'll edit my post when I type up my thought. <3
EDIT:
Okay, I came up with some quick ideas:
1.) They are beginning a school year at a private school for those who are "mentally gifted", as the school calls it. They could be in training to become something, or it could just be regular school.
2.) It's summer break!
3.) The gifted humans are struggling to fit in at their public school, and their talents are beginning to strengthen in power.
Variation:
The gifted humans are struggling to fit in at their public school, and their talents are beginning to strengthen in power, when a mysterious letter with an invitation arrives...