Language, Study Guide, Children's Book

This entire series is great for self study as it has exercises from basics to exam examples. The book itself gives you advices and a clear way of advance. I recommend it as I also was able to approve N3 this year.

This one is the holy grail for anyone who want to study japanese grammer in very depth because this book contains every grammer points that any need in level N5 and N4 JLPT and the explanation and examples are also very helpful.