Saitō Tatsuoki features as a minor character within the series, visually characterized by freckles, a prominent hair antenna, and an overweight physique, consistent with the show's comedic and stylized design aesthetic. Historically, he served as the third daimyō of Mino Province, succeeding his grandfather Saitō Dōsan and father Saitō Yoshitatsu. Tatsuoki inherited leadership at the age of 13 in 1561 but proved an incapable ruler. His familial link to Oda Nobunaga existed through his aunt Nohime (Dōsan's daughter and Nobunaga's wife). Tatsuoki's rivalry with Nobunaga culminated in his decisive defeat at the 1567 Siege of Inabayama Castle. Accounts diverge on his surrender: one depicts him abandoning the castle and fleeing down the Sunomata River, while another states he negotiated terms assuring leniency before marching out with his retinue. Exiled, Tatsuoki sought refuge with the Asakura clan. He died at age 25 during the 1573 Battle of Tonezaka in Echizen Province. Within the anime's narrative, Tatsuoki appears among the ensemble cast of historical Sengoku-period figures, with no significant character development or expanded backstory depicted across the series or related media.