Mai Kazuki hails from a family steeped in stage magic. Her parents run a small snack shop, while her grandparents head the professional magician troupe Magic Carat. Her mother once performed with the troupe before stepping back for family life. Mai idolizes the legendary magician Emily Howell and dreams of becoming a skilled stage magician herself. Yet, significant clumsiness and a lack of proficiency in conventional tricks during her early years hinder her active participation in the family's performances.

A pivotal moment arrives when Mai encounters a floating light near a heart-shaped mirror during her grandparents' move. This light manifests as the mirror fairy Topo, who takes residence in Mai's stuffed flying squirrel toy. Topo grants Mai a magical bracelet adorned with symbols of the four card suits. This bracelet conjures a wand enabling Mai to transform into an older, teenage persona: "Magical Emi." In this form, Mai gains enhanced coordination, mastery over real magic, and a distinct appearance, including altered hair color.

Mai primarily uses her Magical Emi identity to support Magic Carat's struggling shows, rapidly becoming their star attraction. Her magical abilities draw public attention, even television opportunities, demanding careful management of her dual identity. Family, friends, and troupe members remain oblivious that Emi is Mai's transformed self, believing them separate individuals. This secret complicates Mai's daily life, requiring creative solutions to balance commitments and avoid suspicion.

Personality-wise, Mai exhibits high energy, determination, and an occasional quick temper, especially when teased about her clumsiness or dismissed due to her age. She possesses a strong sense of justice and kindness, often using her magic to help others. Her Magical Emi persona reflects her aspirations: confident, graceful, and publicly adept. Despite her magical advantages, Mai retains her core values in both forms, refusing opportunities that compromise her integrity, like solo singing engagements excluding her Magic Carat colleagues.

Key relationships shape her experiences. She shares a typical sibling dynamic with her younger brother Misaki, who occasionally displays greater natural talent for conventional magic. She develops a close, often bickering friendship with Sho Yuki, a talented young magician in Magic Carat who dreams of becoming a boxer, viewing him as an older brother figure. Topo serves as both her magical guide and confidant, aware of her secret and offering guidance, while enduring mishaps like being treated as a toy by Misaki. Her school life includes navigating the obliviousness to a classmate's crush.

Mai's development centers on reconciling her dependence on magic with her original dream. Early reliance on Emi's powers provides opportunities but sparks internal conflict; victories achieved through real magic feel unearned. This culminates in her decision to relinquish the transformation bracelet and magic permanently. She chooses to pursue her goal authentically, through dedicated practice and growth rather than supernatural shortcuts, aiming to honor Emily Howell through genuine skill.

Her magical abilities exist exclusively within her Emi form, activated by a specific phrase and wand movement. These powers enable stage illusions and practical problem-solving but deplete over time, requiring rest between uses. The magic never transfers to her untransformed state, where her inherent clumsiness persists.

In her story's conclusion, Mai embraces a future focused on honing real-world stage magic skills without magical aid, symbolizing her maturation and commitment to earning her place as a magician through perseverance.