Kaon (かおん), also known as "Kaon of the Lunar Spiral", is the Absolute Angel Murakumo (a reference to the mecha/deity Ame no Murakamo from Kannazuki no Miko). The sword of the head of the Higashigetsu Fūma Witch Academy, she stages attacks on Kū Shiratori and her friends by order of Mika Ayanokōji, although she does not seem to feed on the energy of innocent bystanders as Tarlotte does. Himiko usually appears with her and, despite the fact that she is Mika's sword, she harbors a deep affection for Himiko, although she initially denies that their relationship is of a romantic nature(likely due to knowing that Mika would punish Himiko even more deeply if she admitted such).
She displays a strong desire to protect Himiko, even at a cost to herself. She has her Absolute Angel mark on her left arm. At one point, Mika removes Kaon's 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 change Kaon's personality and sever her emotional bond with Himiko, to the latter's great distress. Nevertheless, Kaon's true nature and affections still exist underneath the damage done to her by Mika's torments, and she soon overrides Mika's work to protect Himiko from harm. Her mark is restored when Himiko kisses Kaon, expressing her love for her.
In the second special of the anime, Kaon goes to visit Himiko and Himiko draws her nude with a blanket. They talk about if they can visit more, but Kaon has to be repaired, a process that could result in memory loss or death; Himiko cries tenderly and Kaon puts her arms around her and says "Don't worry, because I'll be in here." (Meaning in Himiko's heart). Himiko tries to kiss her, but Kaon said "Save that until I come back." Kaon leaves, but Himiko grabs her hand and kisses her anyway. In the ending scenes she and Himiko lives together like their previous reincarnation and in the sixth special, they're shown in a jewelry store, buying two pendants. She is seen with Himiko enjoying a private hot spring, presumably under her orders. When Himiko expresses her worries, Kaon gently leans her into her body. Kaon then threatens to kill the girl for disturbing the lovers' moment but is subdued by a sweet kiss.
- Kaon (歌音?) is derivative of Chikane Himemiya (千歌音?) (Kaon's alter ego) in Kannazuki no Miko and it has has been said to be Chikane's reincarnation.
- In the sixth special, the pendants that Himiko and Kaon purchase do not only link up to form a heart, but also bear pink seashells; the exact same ones worn on the necklaces Himeko Kurusugawa and Chikane possessed in Kannazuki no Miko.