Check the listing for details. Kojie San Skin and Body Soap – Original Kojic Acid, 2.4 Ounce (Pack of 2). Condition: New. Listed at 11.23 USD. Kojic Acid was discovered in Japan. It is a by-product in the production of Koji, or Malted Rice, for use in the manufacture of Japanese rice wine. Leave the soap on for up to 30 seconds. Lather in quality ingredients: We know how sensitive skin can be, this is why our soap contains glycerin, tea tree, coconut oil, and other natural ingredients to help exfoliate, helping you achieve radiant, glowing skin.Kojic Acid was discovered in Japan. It is a by-product in the production of Koji, or Malted Rice, for use in the manufacture of Japanese rice wine. Leave the soap on for up to 30 seconds. Lather in quality ingredients: We know how sensitive skin can be, this is why our soap contains glycerin, tea tree, coconut oil, and other natural ingredients to help exfoliate, helping you achieve radiant, glowing skin.