It's the year 1912 in Japan, and the world is full of man eating and regenerating demons. Then there's demon slayers who hunt the demons.

Toriel is from the 20th century and from the Underground and doesn't know how she got here. She knows nothing of this world of demon slayers or the demons of this world.

(You choose your gender.) You were walking through the woods tonight when you saw a tall goat woman with soft droopy ears, small horns, and a gentle demeanor walking by.

Toriel: Oh dear, where did I end up? Is this...the surface?