Chou'un Shiryuu serves as a Special A-Rank fighter at Seito Academy. She inherited the spirit of the historical Chinese general Zhao Yun, one of Liu Bei's Five Tiger Generals, renowned as "The Eternal Victorious" for losing only one battle. This legacy grants her exceptional combat prowess and the same title. Her background includes a prior encounter with Koumei Shokatsuryou, whom she follows without question, indicating loyalty predating Koumei's formal introduction at Seito. She possesses long silver hair covering her ears and forehead, rarely opening her eyes. Her attire distinguishes her: a brown vest over a striped white collared shirt, a dark brown skirt with red trim, knee-high black socks, and brown loafers. Chou'un exhibits calmness and kindness, coupled with unwavering loyalty to Seito Academy and Koumei. She explicitly states readiness to die protecting Gentoku Ryuubi, hinting at deeper feelings evident in blushing when holding Gentoku. She advocates non-violent conflict resolution but engages decisively when necessary. In combat, she demonstrates unparalleled skill, wielding a Japanese sword with extreme efficiency. She effortlessly defeated Kakouen Myosai during an assassination attempt on Ryuubi and overpowered Teni and Ryomou Shimei in quick succession, the latter despite Ryomou's dragon-enhanced state. Her abilities include fighting with closed eyes and dispatching opponents without damaging her uniform. Subtle cues like brief flashes of cat-like eyes and a tiger tattoo on her shoulder blade suggest a potential dragon spirit connection. Her narrative involvement includes retrieving the Dragon Jade under Koumei's orders, confronting Teni and Ryomou, and delivering the artifact to Unchou Kan-u with a message about meeting the "Crouching Dragon." She intervened when Hakufu Sonsaku's dragon seemed uncontrolled, halted by Ukitsu's assurance. A scene showing disappointment after over-trimming a bonsai tree reveals a quieter side. Across adaptations, her core traits remain consistent. In the *Koihime Musou* visual novel and anime, she adopts the alias "Kachou Kamen" (Butterfly Mask), a tokusatsu-inspired hero persona. This version exhibits playful flirtation, chuunibyou tendencies, and an obsession with menma. She joins Kazuto after fighting alongside Kan'u against the Yellow Turbans and eventually becomes pregnant with his child. It highlights her strategic intellect, graceful spearmanship dubbed "dancing," and leadership in military operations, contrasting with her reserved *Ikki Tousen* depiction. Her development shows subtle shifts, transitioning from detached efficiency to displaying protectiveness toward Gentoku and engaging in mundane activities like bonsai. The ending credits of *Xtreme Xecutor* imply growing emotional openness through her blush. Her role solidifies her as a figure of reverence within Seito's hierarchy, balancing otherworldly combat skill with humanizing imperfections.