Hidaka region

Kelp, salmon, herring, kanpyo (dried gourd)

In Hokkaido, which is one of the largest producers of kelp in Japan, "Kombu-maki" (kelp rolls), in which fish such as salmon and herring are rolled in kelp, has taken root. Kombu-rolls are often made with Hidaka kelp, which is soft and low in fiber content and is found in the Hidaka region. Today, kelp rolls are also made throughout Japan, and are often served at New Year's. Hokkaido accounts for 90% of the nation's kelp roll production.
Hokkaido is Japan's leading kelp producer, accounting for 90% of the nation's total production. Kombu has a long history, and is even mentioned in the "Shoku Nihon Ki" (Records of Japan) in the 16th year of the Enryaku era (797). In the Kamakura period (1185-1333), trading ships began to carry kelp between the Matsumae area and Honshu, and in the Muromachi period (1333-1573), kelp was carried to Tsuruga in Echizen Province (present Fukui Prefecture) and then to Kyoto and Osaka. Later, as kelp fishing flourished during the Edo period (1603-1867), consumption of kelp increased, and it became a major transport item on the "Kitamae-bune," a Kansai route around the Sea of Japan. Kombu-maki" was made by combining kombu with herring, whose catches were high during the same period, and salmon, a specialty of Hokkaido, and became a local dish of Hokkaido.

Kombu is often eaten during the New Year's holiday to bring good luck, as the word "yorokobu" means "good luck. It is also often used as an ingredient in dishes for Hare (festive) occasions, as it is written "yorokobu" (meaning "good old kelp") to convey a wish for longevity, or "kobu" (meaning "child") to express a sense of prosperity for one's offspring.
Herring is also considered to be a food of good luck, and herring "kombu-maki" (kelp rolls) are often included in osechi dishes. Because herring used to be as important as the parents who kept life together as a preserved food during the harsh winters of Hokkaido, it is also written as "nishin" (meaning "two parents" in Japanese), which is also a wish for the fulfillment of children and the prosperity of offspring. In addition, "kombumaki" made from dried kipper has traditionally been valued as a winter preservation food.

After returning kelp and kanpyo to water, the fish is wrapped in kelp, tied with kanpyo, and boiled in sugar, soy sauce, and sake. The fish wrapped in kelp are mainly salmon and herring, but depending on the region and household, shishamo and chica are also used.

(Outline of the people who have passed down the tradition, preservation groups, use of SNS, modern efforts such as commercialization, etc.)
It is famous throughout Japan as an ingredient of Osechi dishes, and is eaten not only in Hokkaido but also in other parts of the country. It is often made at home, but nowadays it is also available at supermarkets.