Interesting reply. Have you seen Blasians/half Black half Asian who end up looking like him?
You are right, he is not from the Khoisan tribe or in Southern Africa. But you are in the right direction. Keep guessing.
Malagasy people in the country Madagascar were actually from Borneo, Indonesia and they migrated westward on Indian Ocean towards Madagascar and they also settled on other African islands such as Seychelles Islands, Comoros Island and later on they admixed with the East Africans, they also landed in East African countries such as Somalia, Kenya, Tanzania, Mozambique, South Africa and then they went up to Atlantic Ocean and migrated to Ghana. The Malagasy people heard probably rumors that there were oceans on the western side of the continent and it was possible to travel by sea around South Africa to Ghana and they wanted to trade with these people. Madagascar Island or Kenya has a much higher Malagasy admixtures in comparison to other countries.
Malagasy Migration
Malagasy people also went to Atlantic where they landed and traded with Ghana.
Malagasy people migrated to Mombasa, Kenya
I've seen half black half asian in the states that do look similar to him however they are a recent admixture.