From the end of the Heian Period, the back section of the toko and uwate were made of leather separately and joined with strings, the longer kakeo (hanging cord) of the two strings was passed through the fastener (the ukeo, or catcher cord) on the opposite side and tied with the shorter one (machio cord).
平安末期以降は、床の背中部分と上手のみを別々に皮で作って紐で結び、繋ぎ目部分から延び、長短二本の紐のうち、長い紐（懸緒）を逆側の留め具（受緒）に通して短い紐（待緒）と結ぶようになった。