In some fiction the are samurai or ninja in the south west United states and in the show Blackflag one of Flints pirate crew carries a katana and speaks Japanese.
I have read of their presence in 16th century Burma: "...Japanese Christians from Nagasaki escaping the persecution of the dictator Hideyoshi Toyotomi. Some of these Japanese Christians were ronin, masterless samurai and they formed a special bodyguard to the Arakanese king." Thant Myint-U - The River of Lost Footsteps (2007)
Check out the story of Yamada Nagamasa, the Japanese samurai/adventurer who became the governor of Nakhon Si Thammarat province in 17th century.
There is even a Japanese village in Thailand that is a refuge of 1000 people escaping the Christian prosecution of Hideyoshi, former soldiers of Itsunari Army that is defeated at Sekigahara (1600) and survivors of Osaka Castle Siege (1615) that saw the end of Toyotomi clan.