縄文時代から続く日本人と大麻Japan's 10,000-Year Cannabis Legacy and the Global Green Rush

As the global “Green Rush” (the opening of the cannabis industry) spreads, many people are drawn to the place of cannabis (大麻, taima) in Japan. Japan too has finally moved to legalize medical cannabis, but where will Japan-grown cannabis go from here?

On December 13, 2023, revisions to the Cannabis Control Act and the Narcotics and Psychotropics Control Act, which had stood for more than half a century, were promulgated, and from December 12, 2024, the use of medical cannabis was approved as a first stage. At the same time, recreational use was met with extremely harsh penalties, and a new offense of “use” was created and made punishable.

The opening in 2025 of what can finally be called a first step toward cannabis legalization in Japan has begun, but in fact the history of the Japanese and cannabis is deeper than you might imagine. This time, I look at that.

In the 20th century, archaeologists investigating the Torihama Shell Mound site (鳥浜貝塚遺跡) on the coast of Fukui Prefecture found traces and artifacts showing that cannabis was in everyday use in the early Jomon period. What they found were a “cord made of cannabis” and “cannabis seeds,” and dating showed them to be about 12,000 years old, which drew great attention to the relationship between the Jomon people and cannabis.

Cannabis pollen has also been detected at a Jomon site of around 9400 BCE in Tsunan, Niigata Prefecture, and cannabis fruit has been unearthed at a Jomon site of 10,000 BCE in Tateyama, Chiba Prefecture. Most of these reports were published from the late 2000s through the 2010s, and further discoveries are expected.

From this, cannabis is thought to have already existed in many parts of the Japanese archipelago by the early Jomon period. Most interesting of all, the traces of cannabis use found at the Jomon site in Fukui turned out to be the oldest among archaeological discoveries around the world.

Astonishingly, then, the “relationship between cannabis and the Japanese” has been shown to span more than 10,000 years.

The “Jomon period,” Japan's own periodization, takes its name from the “patterns on pottery” that archaeologists discovered, more precisely from the age of pottery with cord patterns. These patterns were formed with various cords and threads, and this historic discovery showed that one of them was cannabis.

Since plants were probably not yet cultivated in the early Jomon period, it is reasonable to think this cannabis grew naturally in the archipelago. Even so, it is a fact that cannabis has been deeply involved in the way of life of the Japanese since very long ago.

What deserves attention is its wide range of uses. Whenever cannabis comes up, attention tends to go only to its medical and recreational use in the recent Green Rush, but that is only a small part of its function (its potential).

The Jomon people, for example, lived basically by hunting and gathering, so they could not get food reliably every day. Cannabis, however, grows faster than other plants and has the particular property of growing in many natural environments.

The Jomon people, who knew this property well, used cannabis in many ways in their lives, for food, fishing line, clothing and more. This is the source of a Japanese way of life that fitted cannabis into life as a whole.

Further, from the Jomon period the Japanese did not use cannabis in part. They took in and used every part of it, root, stem, leaf, flower and fruit. This traditional, sustainable way of use deserves attention. The zero-waste movement is now active in the West too, and cannabis for the Japanese can be said to have been a very symbol of zero waste.

At this point it is still not certain whether cannabis grew wild in the archipelago from the beginning. The provisional view is that cannabis, native to Central Asia, came to China long before the Jomon period by the route later called the Silk Road, and may have reached Japan.

Of course, cannabis was not the only thing that supported the Jomon way of life. Still, in step with the global reevaluation of cannabis now drawing renewed attention, it is worth once more exploring the Japanese and cannabis, a relationship of more than ten thousand years.