If a Japanese comes to Germany...

Possession of German blood is therefore essential for admission into the community of German people. A Jew who, during the "System Time," has assumed a German name and adopted the Christian belief is and remains a Jew. Such differences as exist between Negroes, Indians, and others are evident at once. It is more difficult to differentiate races in the case of a people, which consists of approximately similar and related races. A layman generally says that one Japanese looks like another. If a Japanese comes to Germany he too will surely say at first glance that we all look the same. By more precise observation of the Germans we soon notice they do not all look the same. Moreover, they are not differentiated merely with respect to one or two characteristics. We must explain the concept of race somewhat more exactly.

Manuel scolaire de la jeunesse allemande en 1938