Japan's 10,000 Years With Cannabis

On December 13, 2023, the Diet promulgated revisions to the Cannabis Control Act and the Narcotics and Psychotropics Control Act, laws that had remained virtually unchanged for more than half a century. From December 12, 2024, the use of cannabis-derived pharmaceuticals was approved as a first step. At the same time, penalties for recreational possession and use were tightened drastically, and a new offense of "use" was introduced into the criminal code.

Though 2025 marks the first tentative opening of cannabis in contemporary Japan, the relationship between the Japanese people and this plant runs far deeper than most imagine. That history is what I want to explore here.

Back in the twentieth century, archaeologists excavating the Torihama shell mound on the coast of Fukui Prefecture uncovered artifacts showing that cannabis had been part of everyday life as early as the Initial Jomon period. The finds consisted of cord made from cannabis fibers and cannabis seeds; when radiocarbon dating placed them at roughly 12,000 years old, they sparked widespread interest in the bond between the Jomon people and cannabis.

Further discoveries followed. Cannabis pollen dating to around 9400 BCE was detected at a Jomon site in the town of Tsunan in Niigata Prefecture, while cannabis seeds from roughly 10,000 BCE were unearthed from a site in Tateyama, Chiba Prefecture. Most of these findings were announced between the late 2000s and the 2010s, and more will likely come to light in the years ahead.

Taken together, the evidence suggests that cannabis was already present across the Japanese archipelago by the Initial Jomon period. Most striking of all, the traces of cannabis use discovered in Fukui Prefecture have proved to be the oldest confirmed anywhere in the archaeological record worldwide.

The very name "Jomon period" — Japan's distinct historical classification — derives from the cord-marked pottery (jomon doki) identified by archaeologists. The intricate impressions on the clay were made by pressing cords and threads against the wet surface, and archaeological analysis revealed that some of those cords were spun from cannabis.

What commands our attention is the sheer breadth of its uses. When people hear the word cannabis today, attention tends to fixate on the medical and recreational consumption associated with the modern green rush. Yet that represents only a fraction of what the plant can do.

Understanding these qualities intimately, the Jomon people integrated cannabis throughout their lives: as food, as cordage and fishing line, and as clothing. Here lies the wellspring of a Japanese sensibility that wove cannabis into the fabric of life as a whole.

What is even more remarkable is that from the Jomon period onward, the Japanese did not merely utilize isolated parts of the plant. They made use of the entire organism — roots, stalks, leaves, flowers, and seeds — incorporating each into daily life. This traditional, sustainable ethic deserves recognition. In recent years the zero-waste movement has gained considerable traction in the West, but for the Japanese, cannabis was already the very emblem of zero waste thousands of years ago.

The staff there explained things to me in considerable detail. At present, they said, no trace of hemp or ramie from the Jomon period has been detected, but if research advances, one may yet appear. And there is one fact that cannot be overlooked. At the Torihama shell mound, an Initial Jomon site centered on the Mikata Five Lakes, cords have been found that are regarded as the oldest known use of hemp in the world. Although the identification is not yet conclusive, hemp pollen has been detected at the same shell mound continuously from the Initial into the Early Jomon period.