Koi no Umani is a traditional dish that has been enjoyed in the Yonezawa region of Yamagata Prefecture for generations. It is made by slowly simmering carp in a flavorful sauce of sugar, soy sauce, and mirin, a sweet Japanese rice wine used in cooking.
The result is a rich, sweet-and-savory flavor and tender carp meat that gently flakes apart. Koi is also known as a fish that provides a good source of animal protein. For Yonezawa, a landlocked region far from the sea where fresh seafood was once difficult to obtain, carp became an important source of food.
The development of carp culture in Yonezawa is traditionally associated with the efforts of Uesugi Yōzan, the lord of the Yonezawa Domain during the Edo period (1603–1868). In order to secure a valuable source of protein in landlocked Yonezawa, Yōzan is said to have encouraged domain retainers to raise carp for food.
According to local tradition, some households created small ponds near the kitchen drainage area and raised carp using vegetable scraps and other food waste from the kitchen. Such practical methods helped carp farming spread throughout the region and eventually established carp as an important part of Yonezawa’s local food culture.
To prepare Koi no Umani, carp is slowly simmered with sugar, soy sauce, mirin, and other seasonings. Cooking the fish over a long period allows the flavors to penetrate deeply while giving the meat a tender texture.
The dish is traditionally enjoyed as a side dish with steamed rice or as an accompaniment to sake. Its rich combination of sweet sauce and the natural umami of carp gives it the distinctive character of a traditional Japanese home-style dish.
Today, carp farming continues in the Okitama region of Yamagata Prefecture, making use of the area’s abundant spring water. The region’s cold winters help produce firm-textured fish, while the clean water contributes to carp with a clean, delicate flavor and relatively little muddy taste.
Modern carp farming takes advantage of the region’s natural environment, while traditional cooking methods have been passed down through generations. Together, these traditions have helped preserve the distinctive character of Koi no Umani today.
Koi no Umani is more than simply a regional dish. It represents an aspect of Yonezawa’s history, as well as the ingenuity of local people who adapted their food culture to life in a landlocked region.
When visiting southern Yamagata, try this richly flavored simmered carp while discovering the long history of Yonezawa’s carp cuisine. It offers visitors a unique opportunity to experience the region’s culinary traditions through a dish that has been closely connected with local life for generations.