Atsuko Kagari, who prefers to be called by her nickname Akko, is the main protagonist of her story. She is a sixteen-year-old girl from Japan who comes from a completely ordinary, non-magical family. Her life changed when she was young after witnessing a magical performance by the famous witch Shiny Chariot. Deeply inspired by the joy and wonder that magic could bring, Akko made it her life's dream to become a witch just like her idol.

Akko's most defining trait is her boundless optimism and energetic spirit. She is cheerful, spontaneous, and incredibly determined, often rushing headfirst into challenges without fully considering the consequences. This impulsiveness frequently leads to chaotic situations, earning her a reputation as a troublemaker and a "problem child" at the prestigious Luna Nova Magical Academy. Despite her frequent failures and the mockery of her peers who come from established magical lineages, Akko never gives up. She possesses a remarkable resilience, bouncing back from setbacks with her enthusiasm intact. While she can be stubborn and easily angered, especially when someone criticizes Shiny Chariot, her heart is genuinely kind and compassionate. She is fiercely loyal to her friends and cannot stand by when someone is in need, even if it means putting herself at risk. Her approach to magic is idealistic, shaped entirely by the glamorous performances of her childhood hero, which often clashes with the more traditional and academic views held by the school and other students.

Akko's primary motivation is to become a witch like Shiny Chariot, who could make people smile with her magic. She wants to prove that a witch without a magical heritage can succeed through passion and hard work. This dream is tested when she arrives at Luna Nova Academy, where she struggles with even the most basic spells. A significant obstacle is that she unknowingly had much of her innate magical potential absorbed during the very Shiny Chariot show that inspired her, a secret she eventually uncovers. Rather than being defeated by this truth, Akko's determination to create her own magic, defined by her belief in herself, only grows stronger.

Within the story, Akko serves as the driving force that challenges the stagnant and declining traditions of the magical world. Her arrival at Luna Nova disrupts the status quo, as her unorthodox methods and unwavering belief in the wonder of magic inspire change in those around her. She is the chosen wielder of the Shiny Rod, the magical staff once used by Shiny Chariot. This weapon responds not to raw power or lineage, but to the strength of one's emotions and convictions. The rod guides her on a quest to unlock the Seven Words of Arcturus, a journey that forms the core narrative. By unlocking these words, she aims to release the Grand Triskellion, a source of great magic that can restore wonder to a world increasingly reliant on science.

Akko's most significant relationships are with her roommates, Lotte Yansson and Sucy Manbavaran. Lotte, a kind and level-headed girl, often acts as the voice of reason, helping Akko navigate social situations and reminding her to think before acting. Sucy, a deadpan and morbid mycologist, frequently uses Akko as a test subject for her dangerous potions but genuinely cares for her as a close friend. Their bond is tested but ultimately strengthened through shared adventures. Another key relationship is with Diana Cavendish, the academy's top student. Diana initially views Akko as a naive and talentless nuisance, representing the traditional, elitist views Akko opposes. Their dynamic evolves from rivalry to mutual respect as Diana comes to admire Akko's unwavering passion and unique ability to change others for the better, eventually becoming a crucial ally. Professor Ursula Callistis serves as a mentor to Akko, offering guidance and support. Akko is initially unaware that Ursula is actually her idol, Shiny Chariot, which adds a layer of complexity to their bond as Akko learns about her hero's flaws and regrets.

Throughout the series, Akko undergoes significant character development. She starts as a naive fan who simply wants to imitate Shiny Chariot. Through her struggles and adventures, she learns that true magic is not about spectacular feats but about connecting with and helping others. She comes to understand that she must forge her own path and prove herself with her own unique qualities, not by trying to be a copy of her idol. By the end, she matures from a clumsy dreamer into a witch who has earned the respect of her peers and teachers, not through innate talent, but through her indomitable spirit and the strength of her friendships.

Despite her general lack of magical talent, Akko possesses several notable abilities. Her physical durability is exceptionally high, allowing her to survive massive explosions and long falls that would seriously injure a normal person. She is also quite clever in high-pressure situations, often finding creative non-magical solutions to problems. Her primary magical tool is the Shiny Rod, which can transform into different forms, such as a bow and arrow for her signature attack, Shiny Arc. As she unlocks the Seven Words of Arcturus, the rod grants her more powerful spells. She also learns to perform basic magic like metamorphosis, allowing her to transform into animals or other people, and mending magic to repair objects. While she struggles with broom flight for most of the story, she eventually learns to fly, symbolizing her growth and mastery over her own abilities. The ultimate expression of her power is her unwavering believing heart, which the series establishes as the most important ingredient for true magic.