Claire Kagenou

Cid's older sister by two years, 17 years old. She once showed signs of demonic possession, which Cid secretly cured before it fully manifested. However, she was kidnapped by the Diabolos Cult's Orba after he discovered this. She has suspicions about Cid and unconsciously senses his power, though she is unaware of it herself. As a result, she is deceived by Cid's act and treats him as a disappointing younger brother who shows no growth, rigorously training him in swordsmanship. Due to side effects from her cure, her magical power has increased without her realizing, and she has been refining her magic control and sword skills by observing Cid's movements. Her high-level swordsmanship has caught the eye of Iris, and she is being scouted by the Crimson Knights after graduation.

Despite Cid being framed by a scheme and arrested, she pleads his innocence to Iris, not out of dislike but rather an overzealous sisterly affection. She is both a protective figure and worried about his future, often overbearingly caring for him, which can be annoying to Cid. Some members of the Shadow Garden and the Numbers see her as "Lord Shadow's sister" and protect her, secretly giving her special treatment at Mitsugoshi Company stores.

She participated in the Bushin Festival, and after the favorite, Iris, was defeated by Jimina—who then revealed his true identity as Shadow and effectively forfeited—she went on to win the tournament. During a battle in the lawless city with Elizabeth, she was forcibly made to enter a "Possession Contract" by Aurora, marking her right hand with the contract's seal, which she has since been hiding with a bandage.

During the school terrorist incident, she was taken by Nina to Zeta, where she was used as a catalyst for Diabolos's resurrection, and a new magic circle was engraved on her right hand. As of the sixth volume of the book, she is in a coma with an uncertain awakening time.

In the TV anime version, her actions to clear Cid's name become more radical, including being restrained after attempting to storm in. As a result, Rose's appearance in the story occurs earlier than in the original work. Additionally, in the third episode of the second season, she inexplicably ends up wearing a school gym uniform and bloomers when making a contract with Aurora.