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From Small Things to Big History: What Kelp Reveals about Early Modern Japan’s Globalization

SHIMIZU Akira (Visiting Research Scholar)
November 07, 2025

Let me talk of kelp in the Edo period.

In Kamanza Street in Marutamachi there is a kelp merchant called Matsumae-ya. It is a store of great distinction, founded with a royal charter by Emperor Gokameyama in Meitoku 2 (1392), the year the north-south court conflict ended. The present owner is the 32nd generation of the family. Matsumae-ya was a so-called official merchant, who supplied kelp products to the emperor and the nobility. The business remained in Kyoto even after the emperor moved the court to Tokyo at the time of the Meiji Restoration, and it continues to this day. Some of you may be familiar with “Hirome,” a sweet kelp. It was first sold in the Meiji period, and today it is sought after as a quality gift. It is sold at confectioners to cleanse the palate after drinking shiruko

The business trades in kelp under the name of “Matsumae.” One naturally thinks of kelp from the Matsumae region, now Hokkaido. Matsumae kelp was established as a brand early on. It featured in kyōgen drama of the medieval period. In the Edo period, it circulated under the strict control of wholesale guilds. It was transported from Matsumae to Osaka via Shimonoseki by sea. From there it was carried to consumers in Kyoto and Edo. At the same time, across the sea in Qing dynasty China, which was not suited for kelp-cultivation, demand for kelp grew. This was because it contained iodine, effective against thyroid complaints which were prevalent there. Kelp became a major export product out of Nagasaki.

It is not very well known that Toyama medicine merchants played a vital role in the internationalization of kelp. In the 16th year of Kan’ei (1639), Toyama was established as a branch domain of the great Kaga domain. It was plagued by financial difficulties from the start, and sold medicines as a way out. It divided up the entire realm into twenty two sections, entrusting each section to different medicine merchants. One of those sections was Satsuma domain, which also struggled financially. Satsuma at the time was exporting kelp via the Ryukyu Islands to Qing China where demand was high. But in the nineteenth century, it permitted the sale of Toyama medicines in exchange for Toyama acquiring Matsumae kelp on its behalf. For the Toyama medicine merchants, Satsuma domain proved an ideal market, it seems. For a time, kelp secretly acquired in Matsumae was taken to Satsuma on vessels owned by Toyama medicine merchants, and smuggled over to China.

I study food and foodways from an historical perspective; that is to say, my approach is not that of “food culture,” but the study through “food” of all aspects of people’s lives—politics, economics, culture and society. I am interested in the people who engage with “food,” especially the merchants and producers in all places linked to the market. Matsumae kelp tells us a great deal about food and foodways. People from the northernmost and southernmost extremes of Japan were connected by people in the middle. Kelp as “medicine” was smuggled out of Japan connecting people from Kagoshima, the Ryukyu Islands, and Qing China. Food will tell us much more besides.

Hirase Tessai (text) and Hasegawa Mitsunobu (illustrations) “Nihon Sankai meibutsu zue” (1754).
The illustration shows gigantic sheets of kelp, a specialty of the Matsumae region, drying on the roofs of private houses. (Nichibunken Library)

Matsumae-ya today. The words “official merchant” (goyōsho) are visible on the cloth screen. For some of you, the kelp merchant’s cloth screen may bring to mind Yamazaki Toyoko’s first novel, Noren. (Photographed by the author)

This is a lacquer box presented by Emperor Go-Sakuramachi in Meiwa 7 (1770) to the 23rd generation owner in recognition of the shop’s longstanding service. (Photographed by the author)