Kagoshima prefecture: south Amami-Oshima, Kakeroma, north Okinawa, Uke, and Yoro islands.
None known. Inherent intelligibility low with other Ryukyuan languages and Japanese [jpn].
Those over 50 use vernacular at home, but understand and use standard Japanese. Those 20–50 understand the vernacular, but mainly speak Japanese. Also use Japanese [jpn]. Mainly older adults.