Miyuri Tsujidō, daughter of St. Mihailov Academy’s dean, wields her privileged status to dominate peers like Tomo Yamanobe and Mafuyu Oribe, bullying them alongside her friend Hana Katsuragi. Her arrogance and pride, rooted in a sheltered life and craving for validation, cloak insecurities about relying on family influence. She sports long pink hair tied with red odango covers, red-violet eyes, and a notably large bust maintained through strict regimens, though she fears further growth could hinder her.

Her evolution begins when Ekaterina Kurae arrives. Miyuri initially schemes to exploit the newcomer for social gain but develops genuine affection, gifting her lavishly. A pivotal moment occurs during a terrorist attack at her family’s museum: Miyuri strips nude to shield classmates, letting Ekaterina access her soma to defeat attackers. This selfless act transforms her from antagonist to ally. She later bonds with Elizabeth after mistaking her for a boy; though disappointed by the truth, she supports Elizabeth unconditionally, even permitting soma-drawing during battles.

Temporarily gaining qwaser-like powers via an elemental circuit, Miyuri adopts the alias "Lily Kamen," aiding others covertly in a swimsuit and goggles. Despite struggling to control these abilities, she investigates icons and confronts foes like the Helium brothers. Her alliance with Tomo deepens when mutual soma exchange activates Edgar’s future-sight, enabling them to dismantle criminal plots.

Miyuri later hosts events like Ekaterina’s birthday and helps track thieves using Edgar’s foresight. Absent during the final clash with Meteora, she remains active in school life and reunions, cementing her integration. Born June 16 with a surname meaning "street hall," her familial ties underscore her journey. Though initially driven by vanity and insecurity, she gradually emerges as a devoted, albeit imperfect, ally committed to safeguarding her peers.