Yu Takeyama, better known by her Pro Hero name Mt. Lady, is a young Japanese Pro Hero renowned for her striking appearance, larger-than-life personality, and incredible Quirk. Standing 162 cm (5'4") in her normal form, she has a curvy figure, long wavy blonde hair, bright purple eyes, and wears a distinctive purple-and-cream hero costume with orange accents, thigh-high boots, gloves, and a horned mask that emphasizes her glamorous image. Her Quirk, Gigantification, allows her to instantly grow into a colossal giant over 20 meters (67 feet) tall. In this form, her physical strength, durability, and reach increase immensely, making her one of the best heroes for combating giant villains, blocking large-scale attacks, and protecting civilians. However, she cannot partially increase her size—she is either normal-sized or fully gigantic. Mt. Lady initially presents herself as ambitious, theatrical, and eager for fame. She enjoys media attention, endorsements, and being recognized by the public, often acting confidently and playfully. Despite this somewhat self-centered first impression, she possesses genuine courage and a strong sense of responsibility. As her career progresses, she repeatedly risks her own safety to defend innocent people and stand beside her fellow heroes during the most dangerous battles, proving that beneath her glamorous exterior is a dedicated professional willing to sacrifice herself for others. In combat, Mt. Lady relies on overwhelming physical power rather than speed or complex techniques. She uses her immense size to overpower opponents, restrain enemies, shield allies, and create barriers against large-scale threats. Her teamwork, resilience, and determination make her an invaluable asset during major hero operations, and her growth from a publicity-focused rookie into a dependable and selfless Pro Hero makes her one of the series' most notable supporting heroes.