Prologue

It's been four years since peace and prosperity had been restored to the undergrounds where the monsters were once forced to be trapped inside. Long ago, two races ruled over Earth: Humans and Monsters. One day, war broke out between these two races. In the end of a long battle, the humans emerged triumphant. The monsters were sealed away with a magical seal.

All is well until a young girl about our hero, Frisk's age, who has fallen into the undergrounds. Little do the gang find out that danger lurks around every corner in the undergrounds...