You might want to take a look at this page.
It says that Sayomeds are one of the rare breed of dogs and are very expensive in comparison to other breeds. BUT that does not mean you should cross it off your list (becaause I've got a Formosan, which you've probably never heard of).
I think you should ask your friend what the other puppies looked like. If they are
ALL white then you probably are looking at a Sayomed instead of an Akita because Akita comes in different colours (plus white Akita are 'rarer').

You can always get her DNA tested if you really want to!