Family name 克一 (Keyi 
, 克一 ) , in the entire world, is quite a rare cognomen. The cognomen 克一 is characteristic of Sub-Saharan Africa, particularly Gabon, where it is quite a rare surname, Cameroon, and the Democratic Republic of the Congo. Not in comparison with a country's population, it is the most numerous in Sub-Saharan Africa, particularly the Democratic Republic of the Congo, Cameroon, and South Africa. Also, 克一 is the forename as well as the last name.