Salt-sweet preserves used as a topping for rice. つくだに、佃煮
Seafood, seaweed and vegetables are simmered in a thick sauce made from soy, salt and mirin until all moisture is reduced. These preserves keep very well. The flavor is quite intense.
The name originates in Tsukuda-jima, a small island in the River Sumida in central Tokyo, where the product was first made in the Edo-period. (Tsukuda-ni means literally "simmered (preserve) from Tsukuda").
[Ikago no Kugi-ni, a form of tsukudani from Hyogo Prefecture]