The Japanese surnames etymology dictionary.
※ Yamanashi-ken Hokuto-shi Born of a religious stone (Kyouraishi) · Baisho origin. A place name with a record since the Edo period. Tell them that they called it during the Sengoku period in the same place. In the estimation, the place name is from Kiyoishi (Kiyo Rai) who worshiped the stone as a god.