souvenir（Fish boiled down with soy）
Tsukudani
Tsukudani is small fish, shelled clams and lavers that are cooked and
candied with shoyu , mirin , sugar and such. Because of its saltiness and
sweetness, tsukudani is highly preservable and has been favored as a
storable side dish in Japanese kitchen since the Edo period. Tsukudani is
often used for onigiri and ochazuke . Its name came from the area of its
origin called Tsukudajima (current Tsukuda area of Chuo City), which
was the center of fishery in the city of Edo.