Jeanne d'Arc, formally known as Jeanne d’Arc the 30th, descends from Joan of Arc, her lineage preserved when an ancestor evaded execution through a body double during trial. Operating under the alias “Durandal” within the covert organization IU, she seeks to recruit Shirayuki Hotogi by force. Her scheme unravels when Aria H. Kanzaki, Kinji Tohyama, and Shirayuki intervene, resulting in her capture. A plea bargain compels her enrollment as a second-year exchange student in Butei High School’s Informa department. Formal and stoic, Jeanne prioritizes etiquette and composure, upholding traditional values like modesty in attire while donning plate armor in battle. Her stern demeanor belies secret quirks uncovered through interactions with Riko Mine: a clandestine passion for collecting maid dresses and lolita fashion. Though resolute, she exhibits naivety—unaware of her lackluster artistic talent—and rare flashes of warmth when discussing her homeland or fashion preferences. Wielder of the ice-empowered sword Durandal, Jeanne freezes targets on contact, blending martial skill with tactical cunning. She employs deception, including impersonation, to outmaneuver foes. Raised in IU’s matrilineal structure, she maintains ties to her disowned brother Pierre, her loyalty to the organization clashing with bonds formed at Butei High. Her past actions contributed to prolonging Kanae Kanzaki’s imprisonment, intertwining her fate with Aria’s. As a member of Team Constellation, Jeanne applies strategic acumen and ice abilities in joint missions. Historical lore traces her family’s survival to ancestral trickery and links her powers to exposure to Irokane, a mystical substance. This heritage casts her as a warrior bound by duty yet entangled in conflicts between IU and Butei High. Though camaraderie with peers like Riko and Kinji subtly shifts her path, tensions persist between institutional allegiance and personal growth, leaving her ultimate loyalties unresolved.