Mio Tōsaka serves as a member of the Galaxy Princess team, recruited after scouts Lilia Saijo and Hinano Hoshikita discovered her at a restaurant. Her defining passion lies in cosplay and costume creation, where she invests considerable effort to authentically embody cherished characters. This dedication fuels her meticulous design process, driving her to perfect every detail of her outfits and performances for full immersion into each role. Physically, she stands as the shortest among the main cast, with pale skin and striking green eyes. Her hairstyle features two triangle-shaped buns paired with curly twintails, displaying a distinct two-toned asymmetry: grey on the right and light blonde on the left. Longer bangs sweep across the right side of her face, accentuating this unique contrast. Beyond performance, she holds a fondness for owls. Her surname "Tōsaka" (東坂) blends the characters for "east" (東) and "slope" (坂), while her given name "Mio" (ミオ) is rendered in katakana without inherent meaning.