Mai Kazuki, a young girl from a family steeped in stage magic, dreams of becoming a great magician like her idol Emily Howell. Her grandparents lead the professional troupe Magic Carat, while her parents run a snack shop; her mother was once a troupe performer who left the stage to start a family. Despite her natural clumsiness hindering basic magic tricks, Mai persists. Helping her grandparents move, she encounters the mirror fairy Topo residing within her stuffed flying squirrel toy. Topo presents her with a magical bracelet featuring the four card suit symbols, which conjures a wand enabling Mai's transformation into an older, teenage persona: Magical Emi.

As Magical Emi, Mai sheds her civilian clumsiness, gaining remarkable confidence, skill, and poise, along with altered hair color. She uses this magical identity to become the star performer for the struggling Magic Carat troupe, dazzling audiences in stage shows and television appearances by blending magic with musical performances, debuting original songs like "Fushigi-Iro Happiness" and "Anata Dake Dreaming". Yet, her success fueled by real magic breeds conflict. Winning a contest as Emi feels hollow, like cheating, rather than a testament to earned skill. This leads to her pivotal resolution: relinquishing her magical powers permanently to pursue her dream through dedicated practice and hard work as her true self.

Mai maintains close family bonds, caring for her occasionally annoying younger brother Misaki. Her father initially prioritizes academics over her magical ambitions. Within the troupe, she develops a sibling-like rapport with Sho Yuki, often engaging in spirited banter. Classmate Musashi harbors an unrequited crush on her. Mai also confronts societal expectations pressuring her towards domestic skills and future duties as a housewife, a source of frustration. In the crossover OVA "Adesugata Mahou no Sannin Musume", Mai appears alongside other magical girls. A scene depicts her at an onsen with Yuu Morisawa and Persia Hayami, attempting to reverse accidental transformations triggered by kimonos and styled hair through reciting tongue twisters. This appearance aligns with her established character without introducing new background or development specific to the OVA.