Calcifer is a fallen star who was caught by Howl. He didn't want to die, so he struck a deal with the wizard. Calcifer got Howl's heart and a prolonged life, and Howl received full access to all of Calcifer's considerable powers. As it turns out, neither of them liked it after a while, but it couldn't be broken by people who were part of the contract. When Sophie Hatter comes to Howl's moving castle, Calcifer recognizes that she is under a curse thanks to the Witch of Waste and that Sophie has considerable powers of her own of which she is unaware. To break his own curse, Calcifer offers to lift the curse placed on Sophie once she manages to break Calcifer's contract with Howl.

A legendary rakugo performer who is haunted by his past. He refused to take in any apprentices until he met Yotarou. As a child, Bon had originally trained as a dancer until damage to his leg left him unable to dance. Bon's mother, a geisha, sent him to train as a rakugo performer under the Seventh Generation Yakumo Yuurakutei alongside Shin, a boy who shows up unexpectedly and is accepted on a whim. While he proved to be adept at the basics of rakugo, and possessed impressive potential to memorize stories, his performances were stiff and lacked emotion and passion. Shin, with his impressive love for rakugo, quickly overtook him. As an apprentice, he was given the name "Kikuhiko." In an attempt to find his own style, Kikuhiko began performing 'bawdy and erotic' stories and discovered his strong ability to personify feminine characters.