Gongtonggo, translated to common language or lingua franca, is a creole of Japanese and Korean in a near future where both countries have merged to create one nation. Gongtonggo is mostly spoken in terretories that are under japo-korean reign, but are not native korean or japanese. Japanese and korean are both recognised as national languages besides Gongtonggo and it's not obligatory to learn Gongtonggo though most people do learn it as a second language in middle/highschool.