[2] Some of the earliest pottery in the Kantō region has been found in this Kofun, giving its name to the type.

These Proto-Jomon sites are distinguished by pottery that predominantly features fiber or cord impressions.

This layer has both early Jomon pottery types like Inaridai, Haijima, and Tado I and other artifacts.

[5][6] In the Kanto valley of Japan, the Inaridai is some of the oldest pottery found.

The Inaridai pottery dates back to just after the start of the proto-Jomon period.