Aisa Himegami, marked by tragedy and supernatural duality, wields the cursed ability "Deep Blood," an intoxicating scent that compels vampires to attack her—only to crumble upon contact. Born a Gemstone, a rare natural esper untouched by Academy City’s experiments, her past is steeped in devastation: a decade before the series, her village was transformed into vampires by one fearing her power, then annihilated when drawn to her blood. This trauma forged her isolation and guilt, driving her to Academy City to suppress her lethal magnetism. Her striking appearance—long, straight black hair in a traditional hime cut and a miko ensemble—is tempered by a British Puritan cross necklace from Necessarius, worn to neutralize her ability. Reserved yet unexpectedly expressive, she reveals flashes of gluttony, like impulsively purchasing every hamburger at a restaurant, or subtle joy through faintly curling lips. Initially attending Kirigaoka Girls’ Academy, she was abducted by the Cult of Science and exploited by alchemist Aureolus Izzard, who dangled the promise of suppressing her power in exchange for luring vampires. Rescued by Kamijou Touma, she develops unspoken affection for him but battles self-doubt, convinced her lack of combat prowess renders her a burden. This insecurity nearly drives her to withdraw from others until friends affirm her worth beyond utility. Her journey intertwines with pivotal arcs. At the Daihaseisai Festival, Oriana Thomson’s mistaken perception of her cross as a threat leaves her gravely wounded, requiring Stiyl Magnus’s magical intervention for recovery. Transferring to Touma’s school, she forges bonds like her friendship with Tsuchimikado Maika, though her quiet presence in group settings contrasts with moments of inadvertent humor—choking during meals or accidentally unfastening her bra strap, sparking flustered exchanges. Aisa’s growth centers on reconciling her longing to feel "special" against her perceived ordinariness. She devours self-help books to forge individuality, excels at cooking, yet feels eclipsed by peers’ distinct talents. Her backstory echoes a yearning for purpose beyond her curse, initially envisioning herself as a "magician of fairy tales" to save others—a dream nudged forward by alliances and her gradual inclusion in Touma’s world, where quiet resilience begins to redefine her legacy.