Lu Wutang is a high-ranking member of the Triad, specifically serving as the consigliere, or chief advisor, of the Lu crime family. He first appears as a minor antagonist during the Death Row Prisoners Arc, also referred to as the Casino Battle Arc, where he challenges Taro Sakamoto and his associates to a gambling match. His primary goal at that point is to bring Lu Xiaotang, the daughter of the Triad boss, back to China to assume leadership of the family. After his defeat and a betrayal by his own guards, he shifts from an adversary to a supporting character who occasionally works at Sakamoto's convenience store and provides the group with valuable intelligence.

As a child, Wutang was physically weak and frequently bullied by other Triad members for relying on his intellect rather than brute strength. At the age of eleven, he was rescued by an eight-year-old Lu Xiaotang, who defended him and encouraged him to develop his mental abilities. This formative encounter sparked an intense and enduring devotion to her, which he carries into adulthood. His personality is marked by a sardonic and pessimistic demeanor, and he tends to be unsocial, but his mood brightens noticeably whenever he is around Lu Xiaotang, for whom he holds an unrequited romantic obsession.

Wutang's defining trait is his extraordinary intelligence. He possesses a prodigious memory and exceptional mathematical ability, allowing him to count cards effortlessly and excel at games of chance. In combat situations, he uses his strategic mind to compensate for his lack of physical fighting skill; his overall combat prowess is only on par with an ordinary gang member. One of his most notable feats is his ability to counter Shin Asakura's mind-reading by flooding his own thoughts with dense calculations and irrelevant data, effectively overwhelming Shin's psychic power. This demonstrates that his intellect can be a potent weapon even in a world of superhuman assassins.

His role in the story evolves from a scheming antagonist to a reluctant ally. After losing his gamble with Sakamoto and witnessing the treachery within his own organization, he accepts a position as a part-time employee at Sakamoto's store. From that point onward, he primarily acts as an information broker, sharing critical details about threats such as Kei Uzuki. His character development is subtle but meaningful: he moves from a single-minded devotion to the Triad and Lu Xiaotang to a broader loyalty that includes the Sakamoto household. Despite his limited screen time in later arcs, his presence remains a reminder of the Triad's influence in the world of Sakamoto Days and of the series' earlier focus on comedic, brain-over-brawn conflicts.