As in other books in this series, the "7 days" is the way the book is organized into the days of an imaginary one week trip. You can't possibly learn the book's contents in 7 days. And even if you could it wouldn't help much - too narrow, too little vocabulary, not enough grammar. Cute photos, though. If you're going to Japan for a visit, get a good phrase book; if you really want to learn Japanese, get a course in it. Also check out kwikpoint.com for nifty folders of pictures that you can point to for your travel communications in ANY language.