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. Nattō may be an acquired taste because of its powerful smell, strong flavor, and slimy texture.
According to my son, natto is like someone ate a lot of beans without chewing, and then sneezed. Somehow, I could not finish this breakfast meal. My youngest children refused to even try. Said one: “I thought you were against the idea of eating bugs and other gross things.”