Approximately 2,000 years ago, the Yayoi culture, which was characterized by rice cultivation and the art of making ironware, spread from western Japan to the Tohoku region. However, the Yayoi culture did not reach Hokkaido, where the Jomon culture developed into the post-Jomon culture.
Since the Hokkaido residents at the time had active exchanges with people from other regions, their culture was not only affected by the Yayoi culture from the south, but also the cultures of Sakhalin and the continent to the north, and developed into a culture unique to Hokkaido.

Rice cultivation that did not arrive in Hokkaido

From the end of the Jomon era, people with rice cultivation skills started arriving in western Japan from across the sea. They brought the agricultural culture of rice-paddy cultivation from around the Yangtze River.

The people of the Yayoi culture used Yayoi pottery without any patterns as well as bronze, iron and other metal tools. Approximately 2,500 years ago, the Yayoi culture spread across Honshu (the main island of Japan), and lead to the end of the Jomon culture. However, the Jomon people learned rice cultivation from the Yayoi people and became a mixed race, which is regarded as the ancestors of the current Japanese. It is known that more people in the Kanto and Tohoku regions inherited DNA from Jomon people at that time than in western Japan.

In the Tohoku region, the Yayoi culture declined even after the rice cultivation spread, and some people gave up farming to return to hunting and gathering. Yayoi pottery pieces with a pattern have also been found, showing the influence of Jomon culture. This Yayoi culture did not reach Hokkaido, where rice was not cultivated.

People in Hokkaido continued to use Jomon pottery with a pattern, and adopted the Jomon traditions and lifestyle. In addition, through trading with Honshu, people also obtained ironware and other metal tools that were not part of the Jomon culture, and these helped to develop their hunting, fishing and gathering skills. This culture, which continued from approximately 2,500 years ago up to the 7th century, is called the post-Jomon culture.

Diversity of post-Jomon culture

At the beginning of the post-Jomon era, different cultures were also found in the southwest and northeast of Hokkaido.

In the southwest, people used Esan-type pottery, named after Esan (Hakodate City) in southern Hokkaido, and their culture is called Esan culture. In Esan culture areas, many shell middens with fish hooks and harpoons have been found. This suggests that the culture depended on fishing. Bracelets made of cone shells from the southern seas have also been found at the Usu-Moshiri Site, indicating exchanges with southern Honshu. In the northeast, different pottery than in southern Hokkaido was used, and amber beads were among the burial goods.
Approximately 4,000 amber beads for necklaces (largest number in Hokkaido) have been found at the Takisato-Yasui Site in Ashibetsu City. Some amber found in northern Hokkaido is believed to have come from Sakhalin, indicating exchanges with northern areas.

In the latter half of the post-Jomon era, Kohoku-type pottery was spread all over Hokkaido, and then to the Tohoku and Niigata regions. It is thought that the post-Jomon culture spread to northern Tohoku at that time.

Line drawings that were carved in rock somewhere between the first and fourth centuries have been found in Fugoppe Cave in Yoichi Town. Drawings found in Temiya Cave, Otaru City were once considered to be ancient characters, but now we believe they are also the same type of line drawings. It is still unknown where this culture of carving drawings in rock came from.