Natto is soy beans.

Natto, which originated in ancient China and has been made since the Qin and Han dynasties (221 B.C.-220 A.D.), is made from soybeans fermented by the bacterium Natto (Bacillus subtilis) to make a soybean product that is viscous, has a more odorous odor, and has a slightly sweet taste.

Ancient Book Records

Ancient Japanese book, "Wakan Sansai Toukai," states, 'Natto has been made since the Qin and Han dynasties.' The word "tempeh" was also used in Japan to refer to natto as "edamame," which began with Chinese edamame, and is also found in a wooden slip unearthed in Heijo-kyo.

Since edamame was made and stored in urns and buckets in the nasho of a monastic temple, and then spread by Zen monks from the Qin and Han dynasties to Japanese temples, natto was first developed in temples, and was also known as "dang natto" or "salted natto". Subsequently, natto was developed according to the local environment, such as using soy sauce instead of edamame or soy sauce instead of soy sauce in Japan. In Japan, local specialties such as natto of Dairouji Temple, Daitokuji Temple, Ichijou Natto, Hamana Natto of Daifukuji Temple, and Yabashi Natto of Goshinji Temple have been inherited based on the characteristics of each region.