Yue Ayase is a student in Class 2/3-A at Mahora Academy, known as a highly intelligent bibliophile and member of the Library Exploration Club with Nodoka Miyazaki, Haruna Saotome, and Konoka Konoe. Despite her intellect and philosophical interests, she possesses a strong aversion to studying and schoolwork, leading to poor academic performance that ranks her among her class's five lowest students. This places her in the remedial study group "Baka Rangers," where she is "Baka Black" and considered the de facto leader due to her relatively higher aptitude. This aversion originated when her grandfather's death caused her to view conventional studies as pointless. Yue exhibits distinctive habits, notably consuming unconventional beverages like salt water or novelty-flavored drinks from juice boxes during contemplative moments. This frequent drinking necessitates regular bathroom breaks, influencing her preference for easily removable adult-style underwear such as tie-side panties – a detail her friend Haruna disclosed to her embarrassment. Her personality balances detached observation with loyalty; she supports her shy friend Nodoka in confessing feelings for their teacher, Negi Springfield, though she later struggles with developing her own romantic feelings for him, creating emotional conflict. Her involvement in supernatural events begins during a class trip to Kyoto, where she assists Nodoka during a kissing game involving Negi clones. Witnessing magical phenomena, including an attack on the Kansai Magic Association headquarters, Yue deduces Negi's identity as a mage and Mahora Academy's magical underpinnings. She subsequently requests magical training from Negi and considers forming a Pactio (magical contract), though she initially withdraws upon learning the kiss-based sealing requirement. During the Mahora Festival, her unresolved feelings culminate in a confrontation with Nodoka after a fall in the library. With Nodoka's encouragement, Yue admits her feelings for Negi and forms a probationary Pactio, gaining the artifact *Orbis Sensualium Pictus* (世界図絵, "World Picture Book") – a magical encyclopedia projecting illusory information pages. This artifact aids her rapid progression in magic, which she practices diligently for over three hours daily. As part of Negi's group "Ala Alba," Yue travels to the magical world (Mundus Magicus), where an ambush scatters the team. She materializes near a magical academy, suffering amnesia and a head injury after being struck by student Collette Farandole. Enrolling at the academy under the name "Yue Farandole," she excels magically despite her memory loss. Latent abilities resurface during a tournament security squad competition, where she instinctively activates her Pactio artifact to defeat a monster alongside Collette and classmates. Though still amnesiac, her performance earns her a role in the Ostia Festival's security detail. In the sequel *UQ Holder!*, Yue reappears as an immortal, having ceased aging after forming a Formal Pactio with the immortal Negi Springfield. She participated in the Third War against the Mage of the Beginning, during which she and Nodoka were presumed dead after being overpowered by the entity. Decades later, she resurfaces alongside Negi (now possessed by the Mage) and uses *Orbis Sensualium Pictus* to reveal critical truths about protagonist Touta Konoe's origins. Her magical prowess has advanced significantly, enabling mastery of complex spells like summoning obsidian blades, levitation, and barrier-breaking. Despite her evolved abilities, she retains her blunt, detached demeanor.