During the Jinshin War in 672, Prince Oama, who was shot in the back with an arrow, built a steam bath to heal his wound; the place was called 'Yase' (矢背) in which 'ya' means 'an arrow' and 'se' means 'the back,' or '癒背' (healing the back), it then became known as 'Yase' (八瀬).
弘文天皇元年（672年）の壬申の乱の際、背中に矢を受けた大海人皇子がこの地にかま風呂を作り傷を癒したことから「矢背」または「癒背」と呼ばれ、転じて「八瀬」となったという。