Shiryuu Chouun fights for Seito Academy as a Special A-Rank fighter. She inherits the legacy of the Chinese general Zhao Yun, one of Liu Bei's Five Tiger Generals famed as "The Eternal Victorious" for losing only a single battle before dying peacefully at 72, marking the era's end. This lineage shapes her titles and role. Aged 18, Chouun possesses long silver hair reaching her back, covering her forehead and ears. She typically keeps her eyes closed, rarely revealing glimpses that show cat-like pupils. Her attire includes a brown vest over a white collared shirt with striped accents, a dark brown skirt featuring red stripes, knee-high black socks, and brown loafers. A tiger tattoo is visible on her left shoulder blade, and her measurements are 89-59-87. Kind yet fiercely loyal, Chouun dedicates unwavering service to Seito Academy and Koumei Shokatsuryou, following orders without hesitation. She explicitly vows to sacrifice her life for Gentoku Ryuubi. Despite her combat expertise, she advocates resolving conflicts without violence. Outside battle, she displays a laid-back demeanor, engaging in hobbies like miniature tree care—though she expresses disappointment after over-trimming one. Her interactions with Gentoku Ryuubi imply romantic feelings, highlighted by scenes where she blushes intensely while holding her. In combat, Chouun wields the Youtou Muramasa "Zanryuu" sword, employing the technique Shiden Issen. Recognized as one of the series' most formidable fighters, she effortlessly defeats high-ranking opponents like Kakouen Myosai while defending Ryuubi, often with eyes closed. No opponent has damaged her uniform or presented a true challenge. She acknowledges Unchou Kan-u as Seito's strongest fighter, though their abilities are comparable. Her dragon affiliation remains ambiguous, though her cat-like eyes and combat flashes suggest a controlled connection similar to other dragon wielders. Her narrative prominence emerges in Dragon Destiny when Koumei dispatches her to retrieve the Dragon Jade. She defeats a fatigued Teni in a single strike after Teni's battle with Ryomou. Following Ryomou's dragon awakening, Chouun transports her to Hakufu's residence, entrusting her to Koukin before delivering the Dragon Jade to Kan-u with the message "It is time to meet the Crouching Dragon." She later intervenes as Hakufu's dragon destabilizes, halted by Ukitsu who assures control. She participates in the coalition against Sousou during the Battle of Chibi. Chouun stands among Seito's Five Tiger Generals alongside Kan-u, Chouhi, Mouki, and Kanshou. Her core loyalty centers on Koumei and Ryuubi, with the latter relationship deepening into implied romantic affection, particularly noted in Xtreme Xecutor's ending credits.