Miyuri Tsujidou leverages her position as the director's daughter at the Eastern Orthodox St. Mihailov Academy to assert dominance over fellow students. She craves constant attention and views herself as a flawless figure who must remain the center of focus, fueling significant arrogance and a tendency to target perceived weaker individuals.

Her bullying focuses on intimidating classmates like the easily flustered class representative Fumika Mitarai, as well as Mafuyu Oribe and Tomo Yamanobe, expending considerable effort to marginalize them socially. Accusations about relying on her family's influence or wealth sting her ego due to the underlying truth she recognizes. Her intellectual limitations make her susceptible to manipulation, particularly through flattery, a vulnerability exploited by others such as Ekaterina Kurae.

While rare moments hint at a capacity for caring, her typical behavior involves arrogant conduct that disrupts class dynamics. She often misinterprets peers' silence as fear or respect rather than embarrassment over her actions. Mafuyu Oribe consistently confronts Miyuri's behavior, refusing to tolerate it. Miyuri possesses pink hair and measurements of 88-57-83.

Her character remains unchanged across the series' seasons, OVAs, or related media, defined by her social status, bullying tendencies, and lack of self-awareness. She does not appear in "The Qwaser of Stigmata: Portrait of the Empress." Her narrative function centers solely on antagonizing central characters through persistent harassment without evolution in motivations or relationships.