Yūna Akashi is a student in Class 2/3-A at Mahora Academy, holding student number 2. Her father, Professor Akashi, teaches magic there, while her mother, Yūko Akashi, perished as an agent for Megalo-Mesembria. After her mother's death, her father hid the existence of magic from her and stopped her early magical training, though a childhood memory shows her holding a wand. Athletic and energetic, she competes with the basketball club and joins the sports-oriented group of Makie Sasaki, Ako Izumi, and Akira Ōkōchi. She displays a mischievous streak and harbors an intense obsession with TV shopping infomercials, frequently recording them during class. A defining trait is her "Electra complex," manifesting as a borderline-romantic attachment to her father. She reacts with intense jealousy towards women like Donet McGuiness interacting with him, openly declaring she'll become his bride. Despite this fixation, she maintains a close and caring relationship with him, often looking after his neglected self-care. Her involvement in major events starts during the Evangeline Arc, where she and other sports club members are briefly turned into vampires before being defeated and restored. On the Kyoto field trip, she joins the "Kiss Negi" contest but is quickly detained. At the Mahora Festival's Final Day Event, she surprises everyone by demonstrating unexpected proficiency with dual magic guns, becoming a top scorer in the "Mages vs. Mars" game. Her performance earns fourth place, 300 free meals, and the self-proclaimed nickname "The Kid," gaining recognition from the academy's martial artists. After the festival, she uncovers her father's identity as a mage and his research on Fate Averruncus. She later travels to the Magic World with her classmates. Following a gateport incident, she and Makie are rescued by a truck driver, Johnny-san. To fund their return, they work as waitresses, eventually reuniting with Negi Springfield at Megalo-Mesembria. Learning about pactios, she eagerly seeks a contract with Negi. After initial delays, she becomes his fourteenth provisional partner during the journey, receiving the pactio artifact "Iris Tormentum"—a pair of magic pistols. This artifact enables specialized bullets: the Spirit Transformation Canceling Bullet suppresses beastfolk transformations, and the Magic Suppression Bullet nullifies magic for three minutes per hit. The pactio brings her immense joy, and it is suggested one pistol may have belonged to her mother. During the battle at the Gravekeeper's Palace, she aids in retrieving the Great Grand Master Key. Under the effects of Ako's magical doping, she intercepts petrification darts to protect Makie, resulting in her temporary petrification. She is later freed to assist in awakening Asuna Kagurazaka. Following these events, she fulfills her mother's last wishes by becoming an agent for Megalo-Mesembria, traveling globally on missions and occasionally aiding former classmates. Beyond her artifact, she possesses latent magical aptitude as the daughter of two mages, capable of basic spellcasting without external mana sources like the World Tree. Her basketball training enhances her marksmanship, though her accuracy is noted as inferior to Mana Tatsumiya's. In the spin-off *UQ Holder!*, she has a descendant named Makina Akashi.