I would like to inform you that including "Japan" as an answer for a quiz that prompts you to name countries that were a part of the Japanese Empire seems unfair. I hope the creator of this quiz reconsiders their choice of including this answer.
I would argue that the Japanese army was NOT an OCCUPYING troop in Japan. Hence the clue and the wording seems a bit misleading to me.
Had Nihon (Japan) changed it's name, and that modern day Japan had a different name than 1940's imperial Japan, then having Japan as an answer would have been more defensible.
Aside from this, great and fun quizz. Thank you / Arigatou gozaimasu
Very good quiz, Micronesia almost got me there.