Unagi is the Japanese word referring to the freshwater eel, commonly used in Japanese cuisine. It is mainly consumed in the form of fillets, which are always grilled due to the presence of harmful toxins. The fillets are then spread with a sweet and salty sauce made with soy sauce, mirin, and sugar.
Although unagi is consumed in the entire country, there are slight regional differences in the way the eel is cut and prepared. In Kanto region, the cuts are made from the back, and the fillets are grilled and steamed, while in Kansai the eel is cut from the stomach and the fillets are merely grilled.
Depending on the preparation, unagi can range from crispy to chewy, but it always has a strong salty and semi-sweet taste. It is regarded as a delicacy and an expensive, luxurious ingredient that is mainly consumed in Japan, where the eel has been proclaimed an endangered species.