Mio Tōsaka performs as a member of the Galaxy Princess team. Lilia Saijo and Hinano Hoshikita recruited her after encountering her working at a restaurant. She possesses a strong passion for cosplay and costume creation, dedicating significant effort to authentically embody her favorite characters through detailed craftsmanship. Physically, she is the shortest member among the main cast. Her appearance features pale skin, green eyes, and distinct two-toned hair styled in angular buns with curly twintails. The hair combines grey on the right side and light blonde on the left. Her bangs are asymmetrical, longer on the right side. Her surname, Tōsaka (東坂), derives from the Japanese words for "east" (東) and "slope" (坂). Her given name, Mio (ミオ), is written in katakana script. She holds a noted personal preference for owls as her favorite animal.