Tsukudani is a food which ingredients are deeply shimmed with soy sauce, sugar, syrup, and sweet rice wine. The ingredients vary depending on the region where it is made. Tsukudani using seaweed, small fishes, and clam is most popular. It is a preservable food, and is mostly eaten with steamed rice.
The name tsukudani comes from the Tsukuda island in Edo, current Tokyo, present Tokyo, which was a reclaimed land. Warlord Tokugawa Ieyasu gathered skilled fishermen from Tsukuda village in Western Japan, present Osaka city. The fishermen in Tsukuda island shimmered small fishes and clams with salt or soy sauce, and preserved them to eat.
Tsukudani was offered to the visitors of the Sumiyoshi shrine started to become known. The common people in Edo started to consume tsukudani because of the preservability and cheap price. It was spread nationally when samurai from different regions of Japan brought back tsukudani from Edo to their hometown.
In 1877, when there was a Satsuma Rebellion, the government forces ordered to make volume of tsukudani for military meal. In 1894, when there was a First Sino-Japanese War, the mass production of tsukudani has started. The soldiers who came back from the war were used to the taste of Edo style tsukusadani, and it became a standard side dish and everyday meal at home.
The taste of tsukudani is salty and sweet, and many people prefer to put them on rice. Nowadays, tsukudani is usually readymade, and can easily be bought at supermarkets. However, compared to tsukudani eaten in the old days, the taste is lighter, and the preservability is less. The original tsukudani could be preserved at room temperature even in summer.