One official language, several recognised regional languages
Japanese, without official language status written into law, is unchallenged in the country's public and administrative life. The archipelago is nevertheless more linguistically diverse than it appears: the Ryukyuan languages of Okinawa and Ainu in Hokkaidō, both threatened with extinction, bear witness to the distinct history of regions annexed later by the modern Japanese state, while English is rarely spoken day to day despite being taught universally.
Japanese
No law explicitly grants it "official language" status at national level, but standard Japanese (based on the Tokyo dialect) is de facto the sole language of government, education and the media.
Ryukyuan languages
A group of languages distinct from Japanese (not mutually intelligible with it), spoken in the Ryūkyū Islands (Okinawa); classified as endangered by UNESCO because of schooling in standard Japanese since the Meiji era.
Ainu
A language isolate, historically spoken by the Ainu people of Hokkaidō, recognised as an Indigenous people of Japan by a 2019 law; classified as critically endangered by UNESCO, with an extremely small number of native speakers today.
Korean
Spoken by part of the Zainichi minority (Koreans in Japan and their descendants, about 0.4 to 0.5% of the population), largely descended from immigration and labour transfers during the colonial period (1910–1945).