Orihime Mitsuishi leads Starlight School, a prestigious academy for idols, drawing from her past as "Hime" of the legendary duo Masquerade. The unit soared to fame with the film *Stylish Thief☆Swallowtail* and anthem "Wake Up My Music," only to disband abruptly during their final concert when Orihime removed her mask, while her partner Miya—later revealed as Ringo Hoshimiya, mother of idol Ichigo Hoshimiya and future culinary entrepreneur—vanished without unmasking.

As headmistress, Orihime blends kindness with disciplined guidance, mentoring students with calm authority and meticulous oversight. Though frequently vexed by colleague Johnny Bepp’s eccentricities, she respects his advisory role. Her poised presence contrasts a sharp eye for potential, urging perseverance and the impact of fan devotion as lessons from her idol days.

She sports medium curly brown hair, dark blue eyes, and a signature blue wardrobe—tailored suits paired with a powder-blue scarf. A beauty mark flickers across adaptations, while her name echoes legacy: "Mitsuishi" (light-stone) and "Orihime," the celestial weaver from folklore tied to the star Vega.

Behind the scenes, she masterminds pivotal events like the "Ichigo Hoshimiya Super Live," channeling her grasp of idolhood’s sacrifices—forged when Masquerade’s masked audition partnership fractured under diverging ambitions. Her resolve to nurture talent mirrors her own journey from stardom to mentorship.

Trivia highlights her "Sexy" idol classification in games, a shared voice actor with another spin-off academy headmistress, and the affectionate moniker "Gakuen Mother," encapsulating her blend of maternal care and unwavering command.