Okinawa Koto Music

...During the Goryeo period, the koto was used only in Tang music, but around the time of King Seongjong of the Yi Dynasty, it also began to be used in local music.
[Japan]
The introduction of the Tang Dynasty 13-stringed koto from China during the Nara period marked the beginning of the koto in Japan, and since then, three schools of koto music have emerged: the koto of gagaku, the koto of temple songs or Tsukushigoto, early modern koto music, and Okinawan koto music. However, the structure of the instrument is basically the same for all three, consisting of a large, slender body, 13 silk strings stretched horizontally on top of it (nylon strings and tetron strings have also been used in recent years), and 13 pillars, and it is played with artificial nails placed on the thumb, index finger, and middle finger of the right hand.

*Some of the terminology used to refer to "Okinawa Koto Music" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…牙箏は高麗時代には唐楽にのみ用いられたが，李朝成宗ころより郷楽にも用いられるようになった。
［日本］
　奈良時代に中国の唐制13弦箏が伝えられたのが日本における箏の始まりであり，その後，箏の音楽に雅楽の箏，寺院歌謡の箏ないし筑紫箏（つくしごと），近世箏曲および沖縄箏曲という三つの流れが生じた。しかし，楽器の構造は基本的には三者同じで，大きな細長い胴と，その上に水平に張った13本の絹弦(近年はナイロン弦，テトロン弦もある)と，13個の柱より成り，右手の拇指，食指，中指に義爪をはめて弾ずる。…

※「沖縄箏曲」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報