Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Interesting Attempt, Hackneyed Approach

From an educator's perspective, if you want to learn Japanese without really comprehending it properly, then I highly recommend this book. If you'd like to learn Japanese effectively, properly and in a way that will allow you to grow as a student of Japanese, then don't buy this book. Save your money and instead buy something instead from Hiroko Storm, Peter X. Takahashi or the like. You'll be much smarter for it.