So the only thing I've never particularly enjoyed in Japan was natto, so fermented soybean, and that's what this is, but mixed up with tuna, and some roe, and some plum, and spring onions, and okra, lots of stuff.
Nattō(なっとう or 納豆) is a traditional Japanese food made from soybeans fermented with Bacillus subtilis var. natto. Some eat it as a breakfast food. It is served with soy sauce, karashi mustard and welsh onion. Nattō may be an acquired taste because of its powerful smell, strong flavor, and slimy texture. In Japan nattō is most popular in the eastern regions, including Kantō, Tōhoku, and Hokkaido.