Pretty unlikely for the entirety of the 18th century and most of the 19th century, under the Tokugawa Shogunate Japan adopted an isolationist stance towards the outside world. The only western power allowed to trade in Japan were the Dutch and only at a single point at the port of Nagasaki. Otherwise the country was denied to foreigners. After immense American and European pressure in the 1850s contact with the outside world was restored and Japanese emigration began to the United States after the 1860s. However as late as 1880 there were only around 150 Japanese in the US, most if not all in Hawaii. Mass immigration did not begin until the closing years of the 19th century.

It's not entirely implausible, just very unlikely.

I hate how you can't edit the topics on this damn site. I meant 19th century, but either one works, just bouncing around settings in my head.