I've lived in Japan for over 20 years and the foundation of everything I know in the language comes from this book. Essentially, it's a model of the language with structural examples of model sentences that you'll use every day for the rest of your life here. Spend your first 2 or 3 months writing out the sentences, stick them on a flash card, and study the patterns and you'll be able to speak and write (now with 'henkan' doing the kanji work for you) comprehensible Japanese. Add a decent vocabulary knowledge plus listening (different skills) and you'll grasp the language. Even now I go back to this book. It's that good.