Across the border in Uganda live the Masaba and the Gisu, both closely related to the Bukusu by a shared language and a common culture.
Intermarriage between the Bukusu and these Ugandan tribes is very common and is, in fact, encouraged by the respective communities.
During the Ugandan civil wars of the 1970s, many of the Gisu and Masaba left Uganda for Kenya, mainly to live with Bukusu relatives around the Bungoma area.
After the wars ended, a large number did not return to Uganda, having already started new lives in Kenya.
Of particular note is the substitution of R with L, so that, for example, the verb 'khuufwara' (xuufwara) - to wear [clothes] is now pronounced 'khuufwala', as it is in the Gisu and Masaaba languages.