Wolfgang Hadamitzky is a freelance author of Japanese language learning materials. He has worked as a librarian on the staff of the East Asia Department of the Berlin State Library and of the German Cultural Institute (Goethe-Institute) in Tokyo. Mark Spahn has a background in mathematics, engineering, and computer science and has worked in Japan as a teacher, computer magazine writer, programmer, and translator. He is currently a technical translator and consultant. Hadamitzky and Spahn are the authors of numerous language learning and reference books including The Learner's Japanese Kanji Dictionary, The Kanji Dictionary, and A Guide to Writing Kanji and Kana Books 1 and 2, all of which are available from Tuttle Publishing.
Overall, this book can actually teach you a good deal of Japanese in three months ... it could come in handy if you're the type of student who simply wants to learn Japanese grammar in a short period of time. -- Language Trainers