I recently stumbled upon this post and thought it was interesting, but wanted to fact-check it a bit, since it seems fairly plausible but way too fantastic to be true.
I've seen previous posts in this sub on the subject but was curious if any new(er) information was available, or if historians had any further insight to add.
Thanks for your answers!
Mentioning previous answers is not intended to discourage follow-on discussion. Especially in this case, because I find it fascinating. Follow-on questions, information, and debate is welcome.
The source appears to be Charles C. Mann, 1493: Uncovering the New World Columbus Created Paperback.
"I recently heard that from 1603 onwards Samurai arrived to Mexico to work as guardsmen and mercenaries. How true is this?" at https://www.reddit.com/r/AskHistorians/comments/5wt1eh/i_recently_heard_that_from_1603_onwards_samurai/ . /u/ParallelPain answered, suggesting that it's true. BUT also read "In "1493" Mann states Japanese samurai helped protect silver shipments from highwaymen near Acapulco in the 1600s. Is there any evidence to support this story?" at https://www.reddit.com/r/AskHistorians/comments/4vpdch/in_1493_mann_states_japanese_samurai_helped/ . /u/Gorrest-Fump wrote that "Mann seems to have creatively misread the article - hard to resist such a tantalizing anecdote that underscores his narrative of early globalization" and "The second is that the military service of the Japanese under the Spanish took place in the Philippines, not in New Spain."
As for Chinese, chinos was used for Asians in general, and there were far more Chinese than Japanese in Mexio. Under "How did the people and governments in China, Japan, etc, react when they learned of the New World to the East of them?" at https://www.reddit.com/r/AskHistorians/comments/1hk99t/how_did_the_people_and_governments_in_china_japan/cav7tjn/ , /u/cariusQ writes (but quoting 1493) about the Chinatown in the Plaza Mayor of Mexico City. That quotation doesn't say when it was set up, though.