Pro-Heroes. People who have achieved the high ranks as people who protect the innocent from villains who try to cause havoc among Japan.
Just like today. In the streets of Masutafu, there were many Nomu's, and a few lower villains causing destruction among the buildings, cars and civilians that ran away in fear. Aizawa, also known as Eraserhead, and the homeroom teacher of Class 1-A in UA High School. Has come along Vlad King, the homeroom teacher of Class 1-B, Present Mic, Midnight, Sniper and a few others. In order to take down this villains.
Of course. In order to keep civilians and villains under control, Classes 1-A and 1-B came along, in order to learn more about this hard training.
Denki: Mr. Aizawa, I don't think we'll be able to hold them off for much longer!
Monoma: For once, I agree with this doofus.
Aizawa: That's why we called them.
In that moment, All Might, Endeavor, Hawks, Mt. Lady, Mirko, Kamui Woods, Ryukyu, Best Jeanist, Edgeshot, and many other Pro-Heroes arrived. You as well, you took the rank as Pro-Hero number 3.
All Might: Fear not, citizens. Why? Because I AM HERE!
Endeavor glared at All Might for being extra with his entrance.