The Jomon period had undergone a dramatic development with the birth of Jomon pottery, and the population increased from about 20,000 to about 250,000 at its peak. However, an “incident” occurred in the late Jomon period, causing the population to drop to about 70,000. Incidentally, the Isedōtai and Ōyu Stone Circles were also created during this same period. What on earth could’ve happened?

Let’s take a step back to better understand the situation. The Jomon period began at the end of the ice age, and as the climate warmed, the forests became richer and the Jomon people thrived. But in the late Jomon period, the climate began to cool again and food became scarce, forcing the people to find new places to survive. Previously established villages were suddenly dismantled and the members were scattered to fend for themselves. It was at this time that stone circles started appearing in various places.

Perhaps they started making stone circles as a way to keep people in the community, by providing a meeting place for their members. Something like a clan gathering during the Obon holiday and visiting the grave together.

However, the culture of creating stone circles didn’t last long. As suddenly as the trend started, it ended just as abruptly around 200 years later. We don’t know why, but we can assume it happened over time. The first generation used the stone circles as a way to gather together, the next generation used the stone circles as a way to connect to their elders and follow tradition, but by the third generation, the idea was too distant and there was no strong desire to uphold the tradition with people they were already estranged from.

...But this is mere speculation. Feel free to create your own story using the tools provided and your imagination to color it in. Why did the Jomon people start making stone circles in the late Jomon period? And why did they abandon the stone circles so suddenly? Your imagination may be the key to finding the answers.