Aizawa was just teaching the Class 1-A like always until the Hashiras get suddenly teleported in front for them (BTW your Aizawa's adopted daughter, you can make your own AU)

Sanemi: What the-!?

Aizawa: activates his quirk and ties them up

Mitsuri: Eh??? We're surrounded by demons!!

Shinobu: what is this thing made of!? I can't break it!

Deku: they must be villains..

Bakugo: I bet their with the LOV!