A member of an American family of Enjutsushi, especially skilled in creating and controlling spirit beasts to harness flames. She originally came to Japan to defeat Ayano and take her family's sacred treasure, Enraiha, but decided to stay after she was defeated. She develops feelings for Kazuma after he trains her for her second fight against Ayano. She manipulates myriads of spirits into a single virtual persona which grants her tremendous power. While seemingly capable of creating different spirit beasts, her favorite is Metatron, an angel-like statue equipped with a sword. Kazuma has observed and mentioned that her fighting style is similar to Ayano's, referring to their simplistic and direct attacks, which lack finesse, strategy or tactics. As Ayano's rival in Enjutsushi and for Kazuma's "love," Catherine refuses to beaten in either.