This book is suitable for learners who wanted to study basic Japanese grammar. It will give you some Key Sentences, Formations, detailed notes, explanations, differences and other infos that you can't even find online! The only downside I can think of is that this book is a bit expensive but other than that, it's an excellent book! If you want to study, review and learn basic Japanese grammar, this book is definitely for you!
I read page by page once I finished two-year Japanese language courses in university. Improved my understanding beyond what I already learned in class. One of the writers is actually the writer of the textbook that we used in unversity. Definitely can be a bucket list for enthusiastics Japanese learners out there.