I think this is one of the better Hippocrene Beginner's Series books I've seen. It would be suitable for a good introduction to Japanese for most people. It's laid out differently from most of the Hippocrene Beginner's books I've seen. The right-hand margin of the right page has sidebars that elaborate on or add to the text, such as discussing aspects of Japanese culture, or fine points of the grammar. The left-hand margin of the left page has the current chapter's vocabulary list and definitions.
The author makes a very interesting statement, which is that it takes a Japanese speaker 5 to 8 years to achieve fluency in English, but an English speaker only 2 to 3 years for Japanese. I don't know if this is true or not, but one major thing Japanese has going for it is the very regular verbs and other aspects of the grammar. Unlike English, Spanish, French, and other Indo-European languages, which often have hundreds of irregular verbs, Japanese only has two. For example, 22 of the most commmon Spanish verbs are irregular in the present indicative tense, and of those, 18 are irregular in the subjunctive mood and often several other conjugations, making for a great deal of memory work.
The main difficulty for most English speakers will be that some concepts in Japanese will seem strange. For example, Japanese doesn't have adjectives as we know it. They actually belong to the verb rather than the noun grammatically, and are are conjugated to agree with the verb rather than declined to agree with nouns, as in most languages. And even verbs don't exist as we know them. In Japanese, it's most accurate to think of verbs as expressing the "act of doing something," rather than simple action per se, according to another book on Japanese I just read.
The book is also good for discussing basic Japanese sentence patterns, and these are often highlighted and discussed in the text. However, the book doesn't really go into Japanese particles in depth, which are a more advanced and difficult part of the grammar, but I wouldn't expect that in a beginning book. These are small standalone words that serve various functions, such as marking the subject, topic, or modifying the verb, and other things. For that you'll need a more advanced book. There are at least two books out I've seen devoted just to particles. These are: "Dictionary of Japanese Particles," by Sue Kawashima, and the other is "All About Particles," by Naoko Chino. Both of these are excellent and will help you with this important area of the grammar. Another good book is "Japanese Sentence Patterns," which discusses 50 basic patterns and 69 variations, also by Naoko Chino.
But getting back to the present book, there are 25 lessons or chapters. Each lesson has exercises, self-tests, a vocabulary list, and discussions of grammar. The grammatical discussions aren't too technical but cover the necessary points well. The book also includes an index with all the vocabulary words paged to the text, and a discussion of the Hiragana and Katakana phonetic alphabets. Hiragana is taught to schoolchildren when they're first learning to read, and Katagana is used for spelling important foreign words. All in all a very nice introductory book on Japanese.