Schools in my world of Beckyland can learn just about any widely spoken language as an optional class, though many choose Korean, Mandarin, sometimes Cantonese, or a Romance language.
Mandatory classes are for Japanese and English, which are incorporated into their studies, and they also speak their native creole of Beckynese.
Japanese and English were the languages that helped form Beckyland. When the first people came to the discovered land (c. 1940), they were Japanese and English speakers. Neither could understand each other, so a language naturally formed over time with the help of translators.