Mion Takamine, a Japanese-Argentine born in Buenos Aires on March 3, 1997, grew up independently in Tokyo due to her parents Pietro and Anna Takamine's frequent business travels. This isolation fostered emotional guardedness; she masked loneliness with a cold, manipulative exterior and sharp dismissiveness. As an early Prism Star, her exceptional talent was overshadowed by arrogance. She skipped performances deemed unworthy, including Aira Harune and Rizumu Amamiya's debut, and later interrupted Aira's Tiara Cup victory with a solo show to assert dominance. Offstage aloofness starkly contrasted her flawless, bubbly stage persona. A turning point came during the Summer Queen Cup. After forfeiting a chance to partner with Aira or Rizumu, she blamed herself for their loss to rivals Serenon with K, triggering her first public vulnerability as she cried openly before them. Though she briefly reverted to aloofness, this moment began thawing her barriers. Subsequent interactions deepened the change: initially declining a sleepover for a "sophisticated dinner," she abandoned it to join Aira and Rizumu, sharing high-end macarons, wearing stuffed-animal pajamas, and confessing her crush on Jun Takigawa of Callings. Her evolution continued through team MARs' formation. She embraced collaboration, valuing Aira's fashion insight and Rizumu's athleticism, while confronting personal fears like darkness and supernatural phenomena. Her dynamic with Wataru shifted from cold receptions to playful banter, with romantic feelings gradually replacing her admiration for Jun. Three years later, she balanced MARs with an expanded career: starring in "Magical Mion," mentoring Prizmmy in vocals, supporting Rizumu's marriage to Hibiki, and advocating for its public announcement. Contractual obligations during "Road to Symphonia" forced MARs into the Symphonia Syndicate, severing ties with Pretty Top. After Puretty freed them, a vision revealed her future as Pretty Top's president, inspiring new generations alongside Wataru. Her Prism Shows emphasized cool-themed fashion and technical precision, featuring jumps like "Do-Re-Mi Slider" (aerial keyboard dance), "Golden Star Magic" (star patterns), and "Shining Diamond Dust Burning" (ice-fire fusion). Her catchphrase, "Mion, switch on!" signaled performance readiness.