Perhaps one of the pithiest villains after knowing the reason behind his betrayal against the Kōgon Sect. In his younger days, he was one of the top aces in the Kōgon Sect. He was proud and strong in his faith, until he was forced to kill his Shikabane Hime, who was his fiancee when she was alive. Afterwards, he went into exile for 5 years. No news about him was heard till series of recent events resurrection of many Shikabane cases. He allies with the Seven Stars in order to bring down the Kōgon Sect, eventually becoming the contract monk for Hokuto. However, he was killed by Hokuto in the final episode when he rejects her for his previous Shikibane Hime, causing her to revert back into a Shikabane.
A mysterious black cat that can, at will, be seen or unseen and also can be incorporeal. It always seems to be around Ouri Kagami and he seems to be the only person the cat talks to. It shows up at moments that involve the Shikabane and Shikabane Hime, and gives Ouri clues about them. The intention of this cat is unknown as to whether it is friend or foe. The cat is identical to a pet that Ouri cherished as a child, which died after being run over by a vehicle. Soon afterwards, this cat appeared. Near the end of the series, the cat revealed its true nature with the help of a foe Shikabane who was once a fellow orphan along with Ouri. The cat was made up of a number of children who Ouri's mother had kidnapped trying to fulfill her attachment to this world: to hold her child in her hands. Later, the cat engulfed Ouri in a monstrous form only to help him in the end later disappearing without a trace.
A classmate of Ouri, nicknamed Omune-sama or "Breast Goddess". In the first chapter of the manga she and a few other students visited a "man-eating house", where she was attacked and injured by a group of corpses. She was saved by Makina, and since then she's developed a fascination with death. This fascination leads her to stalk Makina and later Ouri. She also becomes attracted to Ouri and desires to become a Shikabane Hime, so she could be with him forever. In the anime, she was manipulated by Toya because they both thought death was beautiful. Toya's power transforms Kasuga, causing her to become more direct and eventually lead her to kill people at her school, until Ouri and Makina stopped her and Toya. However, they were unable to save Kasuga's life. With her last breath, she asked Ouri to make her into a Shikabane Hime. Her last wish goes unfulfilled as she didn't meet the requirements.