Chou'un Shiryuu, also known as Shi-san, is an 18-year-old female Special A-Rank fighter at Seito Academy. She inherits the title "The Eternal Victorious" from her Three Kingdoms counterpart, Zhao Yun, one of Liu Bei's five tiger generals and Zhuge Liang's right arm. Zhao Yun, renowned for solo charges against enemy lines and losing only one battle in his lifetime (where he still defeated five enemy officers while outnumbered), died at age 72 in 229 AD. Shiryuu embodies this legacy of near-invincibility and loyalty. She possesses long silver hair covering her ears and forehead, typically keeps her eyes closed, and stands 170 cm tall with measurements of 89-59-87 and blood type A. Shiryuu forgoes the standard Seito uniform, wearing a brown vest over a striped white collared shirt, a dark brown skirt with red stripes, knee-high black socks, and brown loafers. A tiger tattoo marks her left shoulder blade. When open, her eyes appear cat-like, hinting at a possible connection to dragon powers shared by other fighters. Her weapon is the Youtou Muramasa "Zanryuu," and her signature technique is "Shiden Issen." Shiryuu displays a kind-hearted and laid-back personality, avoiding unnecessary violence and believing conflicts can be resolved without bloodshed. She exhibits unwavering loyalty to Seito Academy and its leader, Gentoku Ryuubi, stating she would die to protect her. This devotion extends to following orders from Koumei Shokatsuryou without question. Her relationship with Gentoku includes implied romantic feelings, shown in the ending credits of *Xtreme Xecutor* where she blushes while holding her. She also respects Unchou Kan-u, acknowledging her as Seito's strongest fighter despite their rivalrous strength. In *Dragon Destiny*, Koumei sends Shiryuu to retrieve the Dragon Jade. She defeats a fatigued Teni in one strike after Teni's battle with Shimei Ryomou. When Ryomou's dragon awakens due to the Jade, Shiryuu overpowers her, delivers her to Hakufu's residence, and gives the Jade to Kan-u. She later attempts to intervene when Hakufu's dragon runs amok but is stopped by Ukitsu. A non-combat scene shows her contemplatively practicing bonsai trimming, though she over-prunes a tree. She also protects Gentoku from assassination attempts, effortlessly defeating attackers like Kakouen Myosai while defending Ryuubi. Beyond *Dragon Destiny*, Shiryuu appears in later seasons like *Great Guardians*, continuing her role as Gentoku's protector. She features in OVA specials, including comedic hot-spring scenarios interacting with other characters in non-canonical settings. She also appears in the *Higurashi no Naku Koro ni Mei* collaboration event "Maidenlike Impact," a spin-off crossover without direct ties to her main storyline. Shiryuu is part of Seito's modern "Five Tiger Generals" alongside Kan-u, Chouhi, Mouki, and Kansho. Her legacy as Zhao Yun's successor emphasizes themes of loyalty and combat prowess.