Good book for overall N3 grammar, but lacking in grammar details and explanations. Would be much better if it also had a section explaining all the answers for the practice problems.
The Shin Kanzen Master series is a test prep series for the JLPT more so than a general resource for learning Japanese. If you don't care to take the tests, you don't need to bother with these books.
Don't be fooled by how long this took me to 'read'. I mostly had it tucked away out of laziness xD
Also, just to note: I didn't finish this book before taking the N3 (2019), though using it along with other resources, I did pass. Had I gone through this book in its entirety before the test, I would've no doubt gotten a better score.
This book series definitely covers a lot of ground, and the trick questions, comparing very similar grammar, prepares you pretty well for the test.
There are several sections covering similar grammar, along with many quizzes and an answer key. Nuanced differences between grammar are touched on but it's not in depth. (The answer key has no explanations btw, just the answers.) Most of the book is in Japanese, but if you're already at this level, you shouldn't have too difficult of a time going through it. All kanji also have furigana.
I have heard of people passing just fine using these sets of books alone, that said, from my own experiences, I work better using a variety of resources and pooling all that knowledge together. Having a tutor/teacher, or someone else knowledgeable of Japanese would also be extremely helpful in clearing up any questions you might have. (Italki has been a massive help in my studies and I would not be where I am without it. Just dropping my referral link here in case anyone is interested.)
As what you might expect from a test preparation booklet, its contents are quite dry. Unless you're in the studying mood, it can get a little slow. I did, however, find the information in here to be extremely valuable. Each grammar explanation comes with a few example sentences and a small bit of explanation. It's not super deep, which is why I recommend subsequent help, but there were several instances of me being like "OHH!" from reading their explanations.
If you're looking for material to aid you in passing the JLPT, this series does a great job of doing that. While I personally only have experience with this one, just from what I've heard from many others, the whole line is very valuable. (And these books also come highly recommend from one of my tutors too.) It is a shame that test prep is so pricey, but at the very least, they do not sacrifice in terms of quality.
I'm preparing for the N2 next, and have already ordered a few of those books, so I hope to tackle those next. :)
This is really bad for studying grammar. If you have trouble understanding Japanese grammar, it could be the fault of books like these. Change textbook. I only used it for practicing the N3 test, it has a tone of exercises and practice tests, but the explanations given made me confuse what I already knew.
Completely forgot to update this one. It's fine but if grammar isn't your forte, find a tutor, teacher, or friend to help you with the explanations as they're all in Japanese. And all of the grammar points are slightly nuanced so deciding which one works and which one fails is a challenge.