f) learn japanese
Not really a requirement per se, but one's stay in Japan will become 400% more fruitful, meaningful and profitable, if one after a considerable time here, mastered the language of the host country. Not doing so, you would lose out on so much.
That is why keeping Mexicans and other immigrants down with bilingual education is such a disaster and a disservice, rather than a service which they--do gooding libs, think it is. It only hinders. As usual, even with the best intents, everything the progressives touch socially turns to crap.