Green Card Impact

So I read the forum that said you're not allowed to engage in paid activities in Japan while you're there as a foreign traveler. However I'm staying in Japan for an extended amount of time and one of my friends who lives in Japan was excited to have me visit one of her English classes that she teaches. I planned on helping out with the class, but her mother is applying for a US green card and doesn't want to get in trouble by allowing me to "teach." I planned on doing it free of charge, but there's still worry. Will it impact her green card status?

one of my friends who lives in Japan was excited to have me visit one of her English classes that she teaches. I planned on helping out with the class


What exact are you planning to do? Help your friend to PREPARE for class? Or ATTEND with your friend her/his class?

ATTENDING would depend on the school where she/he is teaching if they allow a stranger to come. Most likely not and if they do maybe only for a day or so but not for longer. They can’t have a person without a work permit attend school as a (co-) teacher.

While helping to PREPARE class with your friend, well, nothing to stop you doing that.

In regards to US green card, I am not seeing any connection. Why would a FRIEND of one’s DAUGHTER/SON working potentially illegally in a different country impact your own ability to get a green card for the US???

「you're not allowed to engage in paid activities in Japan while you're there as a foreign traveler.」
If you're not getting paid, you won't get in any legal trouble. While you're prohibited from working while in Japan as a traveler, there's no restriction against volunteering your time, which is what you'd be doing if you're not getting paid.

「one of my friends who lives in Japan was excited to have me visit one of her English classes that she teaches」
Just to be on the safe side, your friend might want to double check with her boss/school that it's OK for you to visit the class. I've worked several English teaching jobs in Japan, and some of my employers would have been fine with me bringing in a special guest from overseas to interact with the class, but others would not have been.

「her mother is applying for a US green card and doesn't want to get in trouble by allowing me to "teach." 」
Assuming you're not getting paid, I can't imagine this would affect your friend's mother's green card application, as you're not in violation of any laws or regulations by volunteering.