Many settlements in western Japan are said to have been moved up hill, that lacked large cultivation areas, at once in the latter half of early period to the first half of middle period in Yayoi period.
弥生前期後半から中期前半は、西日本の多くの地域で集落が可耕地に乏しい丘陵上へと一斉に進出することが指摘されている。