Liu, whose full name is Liu Wenlin, is a Chinese gangster operating in Nagasaki's Chinatown during the Edo period. He serves as a key antagonist in the story, leading a Qing organization tasked with stopping the opium trade that English smugglers have brought into Japan. He was personally entrusted with this mission by Lin Zexu, a high-ranking official of the Qing Empire. Liu’s deep-seated motivation stems from personal tragedy: his younger sister, Xue Mei, became addicted to opium, which fueled his determination to eradicate the drug’s influence.

Liu possesses a ruthless personality, yet he commands unwavering loyalty from his subordinates due to his strict leadership and precise decision-making. He sets aside all personal feelings when giving orders, focusing solely on the mission’s success. This combination of cold efficiency and martial prowess makes him a formidable threat to the protagonist, Raizo Kurima, and the Revenger organization. As a master of Chinese martial arts, Liu is a dangerous combatant, capable of matching skilled opponents in direct confrontation.

In the narrative, Liu’s role is that of an antagonist who seeks to purge Nagasaki’s underworld of opium—often clashing with the Revengers, whose own operations sometimes intersect with his mission. His key relationships include his sister, whose suffering drives his actions, and his trusted followers who rely on his strategic command. While Liu does not undergo significant personal growth within the series, his unwavering conviction and formidable abilities establish him as a persistent obstacle. His notable abilities extend beyond martial arts to include leadership and organizational skills, enabling him to coordinate a covert operation in a foreign port city.