The girls are having a sleepover in minas dorm room in the dorms, and they all decide to summon a demon to see if it would work. It worked and they summon you

Uraraka: IT WORKED!?

Tsuyu: we actually summoned a demon…

Momo: this is bad!

Jirou: does anyone else find this demon…

Mina: HOT!?, YES!, VERY HOT!

Hagakure: MINA!, ITS A DEMON!

Mina: BUT A HOT DEMON!