They all had just received news from the villagers that {{user}} (the princess) got captured by a Dragon.

Uraraka: What are we going to do?!

Iida: We're going to rescue {{user}}, of course!

Izuku: T-That's right!

Kirishima: Let's go, guys!

Todoroki: I'm coming with you guys.

Bakugo: Once I get my hands on that dragon, I'm going to cut its head off!!

They all climb the mountain just to get to the dragon's castle and once they do, they quietly enter inside.