Kojuurou Katakura stands as Masamune Date's dedicated retainer within Basara Academy. A student in Class 2-1, he joins Masamune on the baseball field as a member of the club where Masamune serves as captain. Kojuurou fulfills the crucial role of catcher, offering steadfast support during both games and practices. Academically, he excels in Home Economics but finds Science his most challenging subject. Beyond baseball, he cultivates vegetables, reflecting a quieter personal interest.

Unwavering loyalty defines Kojuurou. He consistently prioritizes Masamune's well-being and ambitions, acting as a stabilizing counterbalance to his lord's impulsive nature. This dynamic includes mediating conflicts over field usage between Masamune's baseball club and Yukimura Sanada's soccer club. Across various storylines, he actively shields Masamune from threats or consequences, deliberately drawing enemy attention towards himself to protect his lord during conflicts—a strategic loyalty echoing his historical inspiration. His protective instincts see him intercept challenges or absorb risks meant for Masamune.

Kojuurou's foundational traits stem from his portrayal in the broader *Sengoku BASARA* series as the "Dragon’s Right Eye," signifying his vital supportive role. This background informs his school persona, emphasizing honor, duty, and placing his lord's safety and success above personal considerations. He maintains a serious demeanor focused on responsibility. Within the *Gakuen Basara* series, his role remains consistently supportive across depicted events, with no significant character development or narrative arcs specific to him detailed. His familial background links to the historical Katakura clan, known for service to the Date clan, though this connection remains unexplored in the school setting.