Mizore Yukihiro, great-granddaughter of Ayaka Yukihiro and heir to the Yukihiro Conglomerate fortune, possesses hip-length blonde hair typically styled in twintails. She demonstrates a perceptive personality, notably commenting that Touta Konoe comes from "a formidable family of heartbreakers" and labeling him "a menace to all women." Her involvement centers on pre-timeskip events. Arriving at UQ Holder's Fairyland Hall headquarters in 2086 alongside Shinobu Yuuki, she resides as a guest while Shinobu joins the staff. During this period, she forms a provisional pactio contract with Touta Konoe, receiving a pactio card artifact. This artifact shares functional similarities with her great-grandmother Ayaka's, though its specific capabilities are unspecified. In 2088, she goes on a date with Touta before his mission against the Mage of the Beginning; he promises to return and attend college with her. Following the 43-year timeskip after the orbital ring incident, her pactio card with Touta turns blank, indicating either her death or existence beyond the solar-system range of the contract's influence. The manga's final chapter confirms she passed away at age 34. No additional media provides further development or backstory.