Kaon, also known as "Kaon of the Moon Spiral," is the Absolute Angel Murakumo (a reference to the mecha/deity Ame no Murakamo from Kannazuki no Miko.) A student from the Higashigetsu Fūma Witch Academy, she stages attacks on Kū and her friends by order of Mika, although she does not seem to feed on the energy of innocent bystanders as Tarlotte does. Himiko usually appears with her. Despite the fact that she is Mika's 'trusted sword', she harbors a deep affection for Himiko, although she initially denies that their relationship is of a romantic nature.

Kaon (歌音) is derivative of Chikane Himemiya (千歌音), her alter ego in Kannazuki no Miko and has been said to be Chikane's reincarnation. She certainly displays a strong desire to protect Himiko, even at a cost to herself, just as Chikane did for Himeko. She has her Absolute Angel mark on her left arm. At one point, Mika removes Kaon's own mark to place her own, after having had her subjected to a torturous process to increase the power of Murakumo and to restrict Kaon to only being able to draw energy from Mika. These events apparently change Kaon's personality and sever her emotional bond with Himiko, to the latter's great distress. Later events show, however, that Kaon's true nature and affections still exist underneath the damage done to her by Mika's torments. Her mark is restored when Himiko kisses Kaon, expressing her love for her.