Translation guide
In Japanese, the term for 'mainlander' depends heavily on context—which island group is the reference point. The most common use is for someone from the main islands of Japan (Honshu, Shikoku, Kyushu) as opposed to Okinawa or Hokkaido. There are also terms for mainland China vs. Taiwan/Hong Kong, and for the main island in a smaller archipelago.
He is a mainlander.
Literally 'person of the inland/home territories'. Historically used in Okinawa to refer to mainland Japanese. Can carry colonial nuances, so use with care.
Mainlanders are sometimes not very familiar with Okinawan culture.
Okinawan language word for 'mainland Japanese person'. Used in Okinawan context, sometimes with a sense of 'outsider'.
There are Okinawan customs that mainlanders don't understand.
Referring to someone from Honshu southward, in contrast to Hokkaido residents.
In Hokkaido, '内地' (naichi) historically referred to the rest of Japan. Still used, but can sound old-fashioned.
In Hokkaido, people from the mainland are sometimes called 'naichi no hito'.
Literally 'person from Honshu'. More specific, but often used loosely for mainlanders.
Referring to someone from the People's Republic of China, as distinct from Taiwan or Hong Kong.
Referring to someone from the largest island in a group, e.g., main island of Okinawa, main island of Hawaii.
Pattern: [island name] + 本島 (hontō, main island) + の人. E.g., 沖縄本島の人 (Okinawa hontō no hito) for someone from the main island of Okinawa.
People from the main island of Okinawa sometimes don't know much about the remote islands.
There is no single Japanese word that covers all meanings of 'mainlander'. Always specify the reference point (mainland Japan, mainland China, etc.) or use a phrase like '本土の人' with clear context.
Mainlanders are surprised by the vastness of Hokkaido.
In Taiwan, mainlanders are sometimes called 'continent people'.