Miso 味噌
Miso - soy bean paste
Shoyu and Miso are the most essential flavouring agent and make particular taste of the Japanese cooking. You would say, why is it particular? Chinese, Korean and other Asian use soy sauce as well. However exactly that is why it makes clear different taste from other Asian cusine. I like to recommend you buying the Japanese soy sauce for Japanese cuisine, Korean soy sauce for Korean cuisine and Chinese for Chinese.