A love story between an 18-year-old girl named Sophie, cursed by a witch into an old woman's body, and a magician named Howl. Under the curse, Sophie sets out to seek her fortune, which takes her to Howl's strange moving castle. In the castle, Sophie meets Howl's fire demon, named Karishifâ. Seeing that she is under a curse, the demon makes a deal with Sophie--if she breaks the contract he is under with Howl, then Karushifâ will lift the curse that Sophie is under, and she will return to her 18-year-old shape.

	Howl is a young, handsome man with bright blue eyes and hair that reaches below his chin. At the beginning of the film, his hair is blonde, but because of an incident while Sophie is cleaning Howl's bathroom, he briefly comes to have orange hair, before it finally turns black through his curse. In the novel, Howl has natural black hair. At the beginning of the movie, Howl is known as rather flamboyant and rumored to have a wicked personality. A rumor that has begun to spread among the residents of Market Chipping even say that he is searching for beautiful, young women whose hearts he may steal and subsequently eat, or that he will devour their souls. He appears rather vain, as well as confident, and does not really seem to care about a lot of others besides himself. Unlike these rumors, he is kind enough to let Sophie clean the castle. As time goes on, his actual personality comes to light, which is that of an endearing, charming and intelligent young man, who, unfortunately, has a tendency to be stubborn and dishonest, as well as to become secretive when it comes to his own life. He commonly avoids getting involved in uncomfortable situations or those which require his committed participation. His vanity is also a very distinct trait, as he is easily irritated if something about himself looks off.
	Sophie is a plain looking 18-year-old young adult, who passes all of her time working in a hat shop. She has big brown eyes and matching hair, tied with two pink ribbons, in a long braid. She has thick eyebrows, and Howl says that her smile is beautiful. She wears a cerulean dress with a white neck and black buttons. After getting cursed by the Witch of the Waste, she gains the appearance of a 90-year-old woman (with a similar appearance to Yubaba or Zeniba) with wrinkled skin and pain on her spine. According to her, she becomes more cunning as she has grown older. She still wears her dress, and now wears her straw hat adorned with a red ribbon. Sophie is a gentle, quiet young woman who doesn't like being in the spotlight. She is mature, and wears clothes meant for women older than her, despite her sister, Lettie's, protests. Sophie also initiates cleaning the massive castle.
	Calcifier is a living ball of fire with eyes and a mouth. He is usually orange-yellow in color, but this appears to change with his emotions and size. Calcifier's size also changes depending on the type and amount of fuel he is running on. He is a very powerful creature himself, with a great deal of magical ability, though cannot move beyond the confines of the hearth in which Howl keeps him without the wizard's help. He's rather unfriendly towards Sophie at the start of the movie, but grows to like her, since she put logs closer to his reach and seemed to be able to keep Howl in line for a bit. He also made a bargain with Sophie that he would try and break her curse, if she would break his, but he could only give her hints.