The foods and drinks derived from koji, which is the rice fermented by aspergillus orizae, are the foundation of Japanese foods, which include sake, shochu, sakekasu, miso, mirin, amazake, soy sauce and shio koji. All of the drinks and foods derived from koji have astonishing medicinal effects. The green tea and natto, which are not related to koji, have also equally great medicinal benefits contributing to the world longest longevity of Japanese. This book describes easy methods to make those foods and drinks from scratch, and how to use those, as well as explains why and how those contribute to healthy life and longevity. In the present revision, three addendums are added: Addendum 1, the newest and simplest method of making koji using microwave; Addendum 2, how to make the sweetest amazake; Addendum 3, how to make soy sauce.