Despite the fact that I cannot answer general grammatical questions concerning my mother tongue, this much I do know: that, unlike in Italian, adjectives in English are NOT interchangeable with nouns.
This rule should be strictly applied when it comes to the topics of race, class, and ethnicity.
Your use of "Jew man" and "a Japanese" are likely to start things off on the wrong foot. No one has any sympathy for racist bigots like you, especially not horrible, foreign ones that probably only came here to steal our jobs in the first place...