Lahan is the adoptive son and biological nephew of Lakan and the adoptive brother and biological cousin of Maomao.

Lahan is a civil official and member of the La Clan who investigates financial and political matters on behalf of his adoptive father, Lakan, and Jinshi throughout the series. His eccentric fascination with numbers and sharp, calculating nature make him a highly valuable informant and strategist, giving the country of Li considerable leverage in political affairs. He is also meticulous in his dealings, pulling strings behind the scenes with minimal involvement, as he prefers not to get his own hands dirty.