Who is Mun Ki from Hawaii and what is their importance?

Mun Ki is Chun Fat Kee's nephew. He is employed as a cook in a brothel on Macao, but later leaves that job when he hears of Whipple's arrival and the need for workers for the sugar plantations. Mun Ki marries before leaving Macao but leaves his wife in China. Mun Ki dies of leprosy after spending his last years banished to a leper colony.