Unadon is a Japanese dish consisting of grilled unagi (eel) fillets placed on top of steamed rice. The eel is grilled kabayaki-style, where the fish is split, gutted, butterflied, cut into squares, skewered, then diped in tare sauce before being grilled.

The tare sauce consists of soy sauce, mirin, sugar, and sake. It provides the necessary caramelization to the fish during the grilling process. Before serving, unadon is typically garnished with sanshō berries on top. In Kantō, the eel is traditionally steamed before grilling, resulting in a more tender texture of the fish, while in Kansai, the eel is simply grilled without prior steaming. 

Unagi nigiri sushi is a traditional type of nigiri sushi. It consists of hand-pressed sushi rice that's topped with slices of freshwater eel that's usually cooked. The dish has a soft texture and a mild flavor. If desired, the eel can be lightly seared with a blowtorch.

It's a nice option for people who don't prefer raw food but want to enjoy sushi. Traditionally, this type of sushi is eaten by hand in a single bite. It's usually accompanied by soy sauce, wasabi, or pickled ginger (gari) on the side.

Anago nigiri is a traditional type of nigiri sushi. It consists of hand-pressed sushi rice that's topped with slices of saltwater eel (anago). Anago is always cooked and the fat breaks down during the process. As a result, the meat develops a very soft consistency and becomes fluffier than unagi (freshwater eel nigiri), which is more chewy and has a dense texture.

When served, anago nigiri sushi is typically brushed with tsume, the reduced broth from cooking anago, which has a sweet, barbecue-like flavor, so it's used as a replacement for soy sauce. Accompaniments to this nigiri sushi include wasabi and pickled ginger (gari) on the side.