야요이 시대
In the years between the end of the Jōmon period and the beginning of the Yayoi period, the sediments that were deposited north of the Uemachi-daichi peninsula / plateau transformed the sea that stretched to the east into a lagoon which was called Kawachi. During the Yayoi period (300 BCE-250 CE), permanent habitation on the plains grew as rice farming became popular.