In the movie the Last Samurai Tom Cruise’s character is asked some questions about native Americans by the emperor which lead me to wonder if the actual Japanese and other asian counties knew about them and exactly how much did they know ?

by BobbyBrownEyez
drylaw

While I can't speak for the 19th century, I've written before on earlier Asian contacts with colonial Mexico - with a focus on the Aztecs - that you may find interesting:

While these don't directly answer your question about exact knowledge (difficult for the 17th c.) they do show traces of early modern exchanges between Asia and Mexico - including cases of native Americans working on the Philippines and of an Aztec scholar describing a Japanese delegation.

Hope this helps!