After the last ice age, during early and middle Jomon period, most of the area which is now Kawaguchi City were under sea level except for the area which is now Omiya Tableland. (Japanese: ) Ancient people living in this area left several shell heaps, in which a lot of shells, Jomon pottery, and pit houses were dug up.

In Kofun period, countless barrows were constructed particularly in the west of Japan. Some barrows were also found in Kawaguchi, the largest one is Takainari Barrow, which was destroyed because of the use of the soil in 1960.