“Do you eat natto?” is a question Japanese ask foreigners. Natto is nebe-nebe : sticky, slimy, slippery, and scary. I dare you to eat natto; it smells like stinky socks, ammonia, bleu cheese, or dark coffee.
Natto (納豆) is one of the few soyfoods which has always been called by its native name in every European language, probably because no equivalent could be found. Most fermented soy products are cultured with molds, but natto is made by fermenting cooked whole soybeans with a bacterial starter (Bacillus natto).
Information from SoyInfo Center, where you can read an exhausive article about the history of natto in Japan.