Mega-nee Akai, formally named Akai Meganee, works as a staff member and manager at Prism Stone in Kirajuku. She possesses long brown hair reaching her shoulders, typically wears short-cut bangs tucked back, has brown eyes, and is defined by her distinctive red glasses. Her name directly reflects this trait: "Akai" means "red" and "Meganee" combines "megane" (glasses) with "nee" (older sister), forming "red glasses."

At Prism Stone, she guides and supports aspiring idols, known for her generally cheerful, kind, and helpful nature, especially towards newcomers. However, she exhibits moments of pronounced excitability or irritation, leading to overreactions when overly enthusiastic or annoyed. She frequently chastises her scatterbrained colleague, Yuzuru Aoba, a fellow Prism Stone assistant and cameraman, establishing herself as a beleaguered authority figure.

A significant shift occurs in Season 2 with the rise of rival store Dear Crown and its manager, Naru Shiawase. Mega-nee initially views Naru as a competitive threat, reacting with annoyance as Dear Crown's popularity impacts Prism Stone. Naru, however, harbors admiration for Mega-nee, later revealing she became a manager inspired by her. Around Episode 75, their dynamic shifts from rivalry to mutual respect, fostering a more cooperative relationship.

Her character appears consistently across the Pretty Rhythm, PriPara, and Kiratto Pri☆Chan installments of the Pretty Series franchise, making her the only figure present throughout. This continuity involves transitions between settings, such as moving from Prism World to real-world locations like Kirajuku. Her core visual traits from the PriPara iteration are retained more closely than in earlier versions. Expanding her presence within the franchise, a distinct male counterpart named Meganii Akai serves as a staff member at Pri☆Chan Land, characterized by a rule-focused and gentlemanly personality.