Compared to the other shichido which were set in the Ritsuryo period, this administrative division was set much later along with the Kingdom of Ryukyu (Okinawa) which became a province after the time of subordination to the Satsuma domain.
これは律令時代から置かれた他の七道と比べると、薩摩藩の付庸国時代を経て令制国となった琉球王国（沖縄）とともにずっと後世の行政区分である。