"Azuki" beans have been grown since the "Yayoi" period. The first time the word ""Azuki"" was used was in the book ""Koziki"". Old Japanese said ""Aka"" for red. And "Azuki" beans were called ""zuki"" because " Azuki" beans get soft when they are boiled. ""Aka"" plus ""zuki"" is ""Azuki"" and this is the origin of "Azuki" bean's name. Another "Azuki" beans has many origins.