Monoethnicity
Monoethnicity is a existence of a single ethnic group in a condition region or country. it is for the opposite of polyethnicity.
China is the largest predominantly monoethnic country; 91.6% of the population are ethnic minorities live in Japan e.g. Koreans, Ainus in addition to Ryukyuans. They represent around 1% of the whole population.
South Korea is a monoethnic country. There are small ethnic minorities that exist in South Korea, where they account for around 1% of the South Korean population. These add around 650,000 Chinese immigrants.
Most Sub-Saharan African countries defecate what would be considered a mono-racial society, but it is common to find dozens of ethnic groups within the same country.
The Yugoslav Wars are identified as having produced territories "de facto & de jure monoethnic nation-states".