Jūzō is a man whose life was defined by a tragic family past and an unyielding, hardened spirit. He rose from humble beginnings to build the renowned Sugaya merchant house, a testament to his determination and business acumen. Despite his success in the public sphere, his personal life was fraught with heartache and contradiction. He was capable of deep love, as seen in his affection for Natsu, an orphan he raised as his own, but also of brutal cruelty, particularly toward his biological daughter, Suzune. His relationship with his biological son, Jinta, was marked by distance, and the two never developed a true parent-child bond, though Jūzō did show slivers of recognition toward him. It is even strongly implied that he later comes to know that Jinta, under the guise of a ronin named Jinya, is his long-lost son.

Jūzō's role in the story is primarily that of a flawed and abusive parent whose actions set the stage for the journeys of his children. His treatment of Suzune was harsh and stemmed from a tragic circumstance: she was not his daughter in the way he had believed, but the product of his wife's rape. This revelation shaped his resentment toward her, prompting Jinta to eventually run away with his sister to protect her from their father. Conversely, his adopted daughter Natsu experiences adoption angst, feeling insecure about her relationship with Jūzō despite his apparent love for her. The complex web of his family relationships, including his hidden history and the fate he sealed by consuming the cursed sake known as Yukinagori, ultimately leads to his downfall.