What are some Japanese last names(or surnames) that sound the "least Japanese"?

How about USA? @Iwasawa. Well I knew somebody with that name and immigration officials in America always made jokes about it when he arrived there.

1)If a last name is a Japanese last name then it must sound a Japanese name -->What!? Not true. What about the last name of chairman of Toyota, Cho, which doesn't sound Japanese last name a bit? 2)Some Japanese names sound a Japanese name --->e.g. mastusmoto. Who would deny this anyway 3)if a last name is a Japanese last name then it can sound nothing like a Japanese name. --->Yep. Mr.Cho of Toyota corp. tells you so. 4)From (2) infer than if a last name is a Japanese last name then it can sound like a Japanese name. 5)From (3) and (4) if a name is a Japanese last then it must be either it sounds nothing like a japanese last name or it sounds like a Japanese last name. 6)If a last name doesn't sound a Japanese last name, then it can sound a last name from another country. --->True; Goldberg doesn't sound a Japanese last name and it sounds a last from somewhere not Japan. 7)From (6) and (5) infer that if a last name is a Japanese last name, it can sound a last name from another country. --->Well for instance the last name Casio is in both Italy and Japan. @Gavin That's one shitty name, but I don't find that to be other than a city name.

No, Japanese family names are always going to sound Japanese, since there has been no "borrowing" of foreign words to make family names. First names, however, can have some leeway. I work with a Naomi. I know a Maria, and a Marina.

How about surnames using "金" like 金田、金城、金山?

My friend's last name is Kyan and she's 100% Japanese. I think it sounds Chinese or something, but it's actually three kanji Japanese last name.