The Nihongo Sō-Matome textbook series is intended for everyone who would like to prepare for the Japanese Language Proficiency Test exams or simply learn Japanese in a structured way. The series features books at every level, from N5 to N1.
N4 level is divided in two parts. Here you will find kanji and vocabulary. Grammar, Reading i Listening can be found in this book. It is enough that you go through two pages a day, and in six weeks you will master the entire material. At the end of each week you will also find a small test. In addition to all the Japanese language exercises, the textbook from time to time also gives tips on how to deal with the JLPT exam stress-free – and points out the most common difficulties and tricky places. Good luck!