Nihongo So-Matome is a Japanese language book series published by ASK, which also publishes the Japanese Graded Readers series.

The series is divided by levels of the Japanese Language Proficiency Test and by subject : Grammar, Vocabulary, Kanji, Reading Comprehension and Listening Comprehension.

Nihongo So Matome is recommended for self-studying. Each book is designed to be studied in 6 weeks, featuring 6 lessons per week though you should study at your own pace and make sure to be ready for the JLPT Test you are aiming at.