According to Wikipedia, Nattō (なっとう or 納豆) is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. It is popular especially as a breakfast food. As a rich source of protein and probiotics, nattō and the soybean paste miso formed a vital source of nutrition in feudal Japan. Nattō can be an acquired taste because of its powerful smell, strong flavor, and slippery texture.
According to Japanese people here, you have passed the “foreigner” test if you can stomach it.
Adam tried it, just watch the video 🙂