According to legend, Kobo-daishi dug the 500th well here. As another legend goes that one evening Ariwara Narihira was frequenting to see his lover in Kwachi, he has seen her rudeness eating rice with a rice paddle, and so he was running away with disappointment. The woman who realized him ran away chased after him to the well in Gohyakuido. Narihira climbed a tree nearby the well to hide up. The woman has dived into the well at the sight of Naihira reflected on the surface of the water.