Gentoku Ryuubi leads Seito Academy as the designated successor of ancient Chinese warlord Liu Bei. She bears the title "Little Vessel" and holds an E-Rank classification among Toushi due to minimal combat skill and lack of tactical intelligence. Her appearance features long brown hair typically in twin ponytails, green eyes, and a notably buxom figure (96-61-92), usually seen in the Seito school uniform. Kind, gentle, and deeply protective of friends, she avoids physical conflict. However, severe emotional distress or threats to allies trigger her transformation into a merciless, sadistic, destructive dragon alter ego that attacks indiscriminately. She struggles perpetually with her dragon spirit, Rairyuu (Lightning Dragon), the most powerful and chaotic of the Three Great Rulers. The manga places her first dragon possession three years before the main story, while the anime shifts it to Kyosho Academy's assault. During this event, Kan'u Unchou subdued her, leading to imprisonment in Seito's basement to prevent harm. Shimei Ryomou's Dragon Jade later reawakened the dragon during Kyosho's attack, causing an uncontrolled rampage until the transformation ended. Her resolve intensifies in *Dragon Destiny* after Kan'u Unchou is captured by Kyosho. Determined to rescue her, Gentoku allies with Nanyo Academy and begins learning to harness her dragon's power. At the Battle of Chibi, she confronts the demonized Sousou Moutoku but is overpowered until Sonsaku Hakufu intervenes. Synchronizing their water and thunder dragon elements, they defeat Sousou, solidifying Gentoku's commitment to her leadership. She returns to her bookish, pacifist self but with heightened responsibility. *Great Guardians* focuses on her relationship with Kan'u, who displays romantic feelings Gentoku largely overlooks or misinterprets, causing friction. Ryofu Housen, possessed by Saji Genpou, manipulates their interactions, leading Gentoku to angrily reject Kan'u's overprotectiveness. Saji then possesses Gentoku, driving her to nearly kill Kan'u. Kan'u's near-death declaration of loyalty breaks the possession. They reconcile when Gentoku gifts Kan'u her favorite book, stating, "I wanted to give my favorite book to my favorite person." In *Xtreme Xecutor*, Gentoku actively strives to become a more capable leader for Seito. This growth is shown when she discovers the injured Bachou Mouki and brings her to Seito for recovery, demonstrating proactive compassion. Her core traits—clumsiness, love for reading, inability to swim, and a hearty appetite—persist, but she exhibits increased determination to protect allies without solely relying on her dragon. Additional traits include her status as a "Chaste Teen" and "Cute Bookworm." Her naivete often leads to slapstick mishaps. The latent threat of dragon-induced outbursts remains, particularly when witnessing allies in danger. The English manga adaptation inaccurately attributes homophobic anxieties to her, a detail absent in the original Japanese version.