The condiments presented in this chapter are all based on fermentation processes involving a microscopic mould, Aspergillus oryzae, in a fermentation medium called kōji. The mould may act alone or together with other moulds, bacteria, and yeast. The condiments arise when these microorganisms break down the macronutrients of plant-based foods like grains and legumes into flavourful aroma and taste molecules, e.g., with umami taste, particularly free amino acids and small peptides. Since these plant-based foods, in contrast to animal-based foods, have no muscular tissues, they are expected to have only very small amounts of free nucleotides. Hence, only free amino acids are contributing significantly to the umami potential of the condiments described in the present chapter. Due to the presence of proteolytic enzymes in kōji it is expected that all products based on this fermentation medium are very rich in free amino acids and small peptides (Ito & Matsuyama, 2021), leading to powerful umami and koku sensations.