Spoke with my Dad and he says as they live and pay taxes in the US they are deemed non residents by default, they didn't apply for anything.

I know that really doesn't answer your question, sorry.

Thanks for asking.

I guess things may be a little different between the US/Canada.

Either way, I talked to several Canadian friends who've been living in Japan for 10+ years. They told me to apply for non-resident status if I'm still in Japan after 2 years and intend on staying for a longer period of time.