Although they have been officially included under the Yi nationality by the Chinese authorities, the Mangbu Nosu possess their own ethnicity, history, and language. This group calls itself Nosu (Black People). Mangbu is the name of a town in Zhenxiong County which is the geographic center of the Mangbu Nosu. One source states that "Mangbu is an ancient tribal name."

In the past, the Mangbu Nosu were one of six powerful tribes who ruled over the region. This alliance rejected Chinese rule of the area, which resulted in centuries of conflict and war between the Nosu and the various Chinese armies that were sent to subdue them. Today, the Mangbu Nosu long for their former glory, but they realize they have no chance of overpowering the Chinese. They view themselves as a defeated people.

Hatred between the Nosu and the Chinese fighters reached such a fever pitch that both sides resorted to cannibalism. Missionary Samuel Pollard, writing in the early 1900s, stated, "A sort of cannibalism is practiced in this area by both Chinese and Nosu. After a fight the warriors who are killed on either side are opened and their hearts removed, perhaps also their tongues, and these are cooked and eaten. It is supposed to be a way of inheriting the courage and valor of the deceased."

Polytheism is the stronghold of the Mangbu Nosu. As a result, fewer Mangbu Nosu have believed in Christ than among other Yi groups in the area. Pollard recorded a sample of the resistance he experienced in 1905: "We crossed the sides of a big mountain ... and finally arrived at the fort of a Nosu landlord called Lohchig. He received us kindly and we stayed there the night, but he is a very unusual local baron. He told us straight he would rather lose his head than become a Christian. He refused all gifts of books, disputed all we said and denied all our attempts to win him over. He stuck up strongly for his religion and defended the worship of idols with great zest."

Although most Mangbu Nosu have refused to consider the gospel, there are about 1,000 believers among them, especially in Hezhang County of Guizhou. Villages there are often divided along religious lines, with Christians forced to live in separate communities.