 The small book, which by 2008 had sold over 20,000 copies, contains information about various types of sake including "nigori", "dai-ginjo", "ginjo", and "hon-jouzo".The book is targeted at novice-level overseas enjoyers of sake and thus contains many pictures and labels of the various drinks.In 2001, Harper took and passed the Nanbu Brewer's Guild Exam thus earning him the title of "toji" or master sake brewer.