First of all, Howl constantly changed himself to try and conform to what society thought was better, and his appearance hides the darker side of him.
Howl would dye his hair blonde and change his eye color because in society blonde hair and blue eyes was considered the natural beauty. This gave Howl a lighter, kinder appearance this hid the darker side of him, when he turned into a black bird. This goes back to how no one is perfect in society and they are not how they seem. This change in Howl shows his internal struggle with good vs evil and being true to himself or conforming to society. Also, Howl wore green ear rings and green is the symbolic archetype of greed. Therefore, Howl is not perfect because he changes his appearance, has an evil side within him, and wears green which is a symbol of
greed. Second of all, the Wicked Witch of the Waste is neither perfect nor how she seems. The Wicked Witch of the Waste, like Howl, changes her appearance to become younger. Showing how she is trying to conform to others by becoming younger to be more accepted. Also, when the glamour was removed and she was altered to her correct age she looked and seemed innocent but the way she spoke and her actions. For example, when the witch smoked it showed her lack of innocence. Therefore, the Wicked Witch of the Waste is not perfect because she seems and looks innocent but because of her actions she is not and she alters the way she looks to become prettier. Lastly, Sophie is not considered perfect because she did not conform to society's norms, conflicted herself some times, and was not how she seemed. Sophie was not considered to be pretty so people ignored her causing her to be less conformed with society. She is imperfect because Sophie appeared to be a caring person, but when she was cleaning she almost drowned Calcifer. That also shows how she was not how she seemed. Over the course of the movie she became more courageous and showing a tougher side of herself. Therefore, Sophie was not perfect and was not always how she seemed. All in all, the theme of Howl's Moving Castle is that when people try to conform to society they are unhappy and not true to themselves and that people are not always how they appear or seem. Throughout the movie it shows you how characters change themselves to become more perfect. Eventually they accept their flaws and realize they are not perfect and they feel better whilst being themselves and not conforming. In essence, Howl is imperfect because he hides his true form by changing his appearance and the motif surrounding him are greed which is a negative trait. Basically, the Wicked Witch of the Waste is vain because she alters her appearance to look younger and become more accepted. Evidently, Sophie is imperfect because she is not considered natural beauty and she conflicts herself at times. Therefore, the theme of Howl's Moving Castle is when people try to conform they are less happy and not true to who they are. Also, another theme would be that not everyone is how they seem.