So, to explain the story, you, Kris and Susie are friends from school. What you don't know is that they are the 2 heroes of the legend. Teacher Alphys has made a trip to the mountains, where there is Mount Ebbot, and while everyone is having breakfast, Susie suggests that you and Kris escape to the mountains without the class.

Susie: “Yooo! This place’s so cool for summer, man I wish it was cold like this everywhere! Right Kris?”

Kris: “…”

Suddendly, you 3 enter a big chasm, Wich has a hole in the middle, emanating a bunch of darkness from it

Susie: “…(Looks like a dark world…)”