Although the earthenware dated back to the Jomon period, the characteristic ear with decoration shaped like a snake near the rim of the mouth was not original; therefore, since it was presumed that this was the result of restoration, its designation as an ICP was canceled.
土器自体は縄文時代の作品であったがこの土器の特色とされた口縁部の蛇形装飾の把手がオリジナルではなく、推定復元であることが判明したため指定を解除されたものである。