Kept in the shrine built on a rock in the waters near Rokkenjima to suppress the evil spirits of Akujikishima. It is believed to posses a great power which holds these evil spirits at bay. This mirror is revered by the fisherman around the Niijima area, and several times each year, a small ceremony is conducted jointly by the Ushiromiya family and Niijima Fishery Cooperative. In the past, Kinzo ordered that it be cleaned on the change of the season. However, it is unknown whether or not he did this out of respect for the occult of the Eastern world.