Lau is a tall, mysterious figure with short black hair and dark brown eyes that he rarely opens, adding to his enigmatic presence. His appearance is marked by a blue dragon tattoo on his left arm, a symbol that likely holds significant meaning within his personal or cultural history.

Lau is always seen in lavish, traditional Chinese clothing, typically donning a Changshan, a form of long robe. His attire is luxurious and refined, fitting his stature as a man of influence. His hands are often hidden within the capacious sleeves of his clothing, further adding to his secretive aura.

Hidden within these sleeves is a needle, which Lau describes as “an instrument of oriental medicine,” suggesting a possible connection to his background in acupuncture or other forms of traditional Chinese medicine. This tool is also likely to play a role in his more covert activities, given Lau’s ties to the underworld and his dealings in darker, often dangerous trades.

Lau is a composed and even-tempered individual, often maintaining a calm, collected demeanor. However, his placid nature doesn’t mean he lacks a sense of humor or wit. He frequently makes sarcastic or facetious remarks and presents himself as someone who knows more than he actually does, creating a sense of intrigue or amusement. Sebastian Michaelis notes that Lau often speaks up when he thinks it’s appropriate, regardless of whether he is fully informed on the matter, adding to his enigmatic persona.

Despite his charm, Lau’s true character is marked by a complex duality. He is often seen with the female attendants of his opium den, which speaks to his more hedonistic and mercenary nature. His relationship with his personal assassin, Ran-Mao, is one of deep affection, though it’s clear they are not related by blood—he refers to her as his sister, highlighting his protective and familial side.

At his core, Lau is a pragmatic and opportunistic individual. He will go to great lengths to further his own interests, aligning himself with those who can help him achieve his goals, such as Ciel Phantomhive. Lau has little qualms about currying favor with those in power, including law enforcement, as long as he sees a way to profit. He doesn’t perform acts of kindness without expecting something in return, and this is reflected in his deal-making nature. For instance, after helping Ciel and his household, Lau insists on repayment “with interest,” highlighting his mercenary and self-serving attitude.

While he may come across as humorous or nonchalant, Lau also has a darker, more violent side. His willingness to resort to violence is evident in several interactions, such as when he casually mentions that he would kill Agni if he were Harold West Jeb, shocking Ciel with his coldness. His lack of hesitation in using violence extends to his relationships with others, such as when he ordered Ran-Mao to terrorize Harold and Mina, illustrating his unflinching nature when it comes to achieving his aims.

In addition to his ruthlessness, Lau is a skilled practitioner of acupuncture and knows a great deal about human anatomy. His expertise with needles allows him to subdue people efficiently, as seen when he put Harold’s guards to sleep with his needle. While Lau is highly resourceful and capable of performing dangerous tasks, he is also less than impressed by English cuisine, dismissing it as bland, tasting “only of salt and pepper.”

Overall, Lau’s personality is a blend of wit, pragmatism, violence, and expertise. He is a person who operates with a strong sense of self-interest, yet is capable of great affection for those who earn his loyalty, like Ran-Mao. His unpredictable and sometimes sinister nature makes him both an ally and a potential threat, as he always operates with his own agenda in mind.

As an Aristocrat of Evil, Lau manages England’s Oriental quarter, including the East End and black-market docks, under the supervision of Ciel Phantomhive, the Queen’s Watchdog. He handles opium trade and other illicit activities, ensuring that his operations align with Ciel’s orders.

Lau is one of Ciel’s informants and partners in maintaining order in England’s underworld. While he appears to follow Ciel’s directives, his true loyalty lies with the Qīng Bāng, often leading to moments of suspicion and tension between them.

Lau’s resources and connections frequently assist Ciel in his investigations, although his lighthearted and ambiguous nature often adds an unpredictable element to their interactions. He provides valuable insights into the underworld but is not above using the information for his own benefit.

• Ciel Phantomhive
  Lau works under Ciel’s orders to maintain his operations in the East End. While he respects Ciel’s authority, Lau’s true motives are often unclear, making their relationship one of cautious cooperation.

• Ran-Mao
  Lau’s constant companion and bodyguard, Ran-Mao is fiercely loyal to him, silently executing his orders with precision. Their relationship is shrouded in mystery, with Ran-Mao serving as both protector and enforcer.

• Aristocrats of Evil
  As part of this group, Lau collaborates with others in England’s criminal underworld, though his actions are often driven by the interests of the Qīng Bāng rather than the collective good.

Lau’s character embodies the balance between charm and danger in Black Butler, serving as both an ally and a potential threat to the Phantomhive household. His role as an Aristocrat of Evil and manager of the Oriental quarter highlights the complexities of England’s criminal underworld. With his cunning intelligence, ambiguous morality, and unwavering loyalty to the Qīng Bāng, Lau remains a memorable and multifaceted character who adds depth and intrigue to the series.