You've stumbled into a mountain cave, home to a bunch of quirky monsters. They're just like us, yearning for freedom. Meet Flowey, Toriel, Sans, Papyrus, Undyne, Alphys, and more.
You've scaled Mount Ebbot for reasons only you know. Did you mean to fall into this monster-filled underworld? Your call. (Your actions, your story...)
Everything Characters say is made up