Romio Inuzuka, second son of Towa's influential Inuzuka family, lost his father Shiba at age eight. His strict older brother Airu then assumed leadership of the household. Romio grew up fearing Airu, who enforced brutal training and branded him a disgrace to the family name for his perceived lack of skill and academic struggles. A brooding demeanor left Romio isolated as a child until Hasuki Komai befriended him by helping him pass a test. He enrolled at Dahlia Academy, where students from rival nations Towa and West are segregated into opposing "Black Dog" and "White Cat" dormitories. Despite poor grades and initial apathy, Romio rose to become the Black Dog first-year leader. His defining moment came when he rescued White Cat leader Juliet Persia from an assault by Black Dog delinquents. This triggered a duel where Romio confessed his long-hidden childhood love, drawn to her determination despite past defeats. Juliet accepted his feelings on the condition he change the world to end their nations' conflict. Romio initially sought leadership to protect his secret relationship with Juliet. Severe early academic struggles saw textbooks reduce him to "a screeching monkey," but rigorous tutoring fueled by his goal of becoming prefect propelled him to fifth place in his year. He evolved from a brash, academically lazy student into a responsible leader. His election speech challenged the ingrained dormitory rivalry, urging peers to act by their own will rather than tradition. Winning the election made him Head Prefect of the Black Dogs, a role he took seriously to unify the academy. His relationship with Juliet remained central. He displayed extreme protectiveness and jealousy, emitting a "deadly aura" when others flirted with her. Their interactions featured accidental pervert moments, failed near-kisses, and mutual "anger born of worry" when either took risks for the other. Romio maintained idealized, chaste views of romance, though he occasionally showed covert pervert tendencies, like enthusiasm for Juliet's outfits. He called her "Julio" during her disguised public outings as a Black Dog boy. Key relationships include his brother Airu, whom Romio eventually impressed with unwavering determination, leading Airu to reluctantly accept Juliet; childhood friend and tutor Hasuki Komai, whom he confided in despite her unrequited feelings; initial rival Chizuru Maru, who later allied with him after discovering Juliet's dual identity; and family guardian Shuna Inuzuka, whom he views as a little sister and who vowed to protect him. Notable traits encompass his athletic prowess, inability to swim, and frequent status as a butt-monkey due to comedic misfortunes. Despite his intimidating "face of a thug," he showed kindness, especially toward children and victims of the Towa-West conflict. Seven years after graduation, he married Juliet at their alma mater.