Often harassed by local boys, one day Sophie is unexpectedly befriended by Howl, a strange but flamboyant wizard whose large home can travel under its own power. However, the Witch of the Waste is displeased with Sophie and Howl's budding friendship, and turns the pretty young woman into an ugly and aged hag. Sophie takes shelter in Howl's castle, and attempts to find a way to reverse the witch's spell with the help of Calcifer, a subdued but powerful demon who exists in the form of fire, and Markl, who protects the four-way door which can instantly take visitors to other lands and dimensions.