The film is about Sophie, an introverted hatmaker in a steam-punk version of Victorian England. She gets swept off her feet by Howl and involved in a feud between magicians amongst a backdrop of a war over a missing Prince from a unknown and unseen kingdom. War becomes simply a representation of pure human evil, and its effects on Sophie and her culture are in the raw death and destruction of carpetbombing and martial law.
Sophie is quickly cursed by the Witch of the Wastes, who is a past lover of Howl, and Sophie is turned into an old woman and is unable to tell anyone of her problems. This, however, seems to be of little relevance, and merely a method to get her to be Howl's cleaning lady and wrapped up in his strange, and honestly wonderful, world.
The troubles with the theme and plot come as the story expands. Is Howl's teacher responsible for the war, or prolonging it? Why is she so two dimensionally trying to harm Howl, and why does she stop when the slightly jarringly pat ending comes about? What you as a viewer cares about is resolved in the end, but the resolution can't stand up to inspection at all. So the imagery is amazing, and the emotions, the represntation of the mystical, all of it is what we have come to expect from Miyazaki. But it seems like he had spent all of his character development upon Howl, Sophie, and Howl's retainers in his castle, and none on the rest of cast of characters. Howl's Moving Castle is a pale comparison to the complex moralities expressed in Mononoke, and it left me looking for more.