The name derived from the old story of a man who was ordered to let a thread through a conch shell. He put the thread to an ant, dripped honey into the conch shell, and let the ant through it. (Ari means an ant and toshi means put through in Japanese.) There is also a folk tale about the huge camphor tree. It was told that the tree stopped the fire of major earthquake in Ansei Era by spreading the water from it.