That being said, if you're looking for study materials for the Japanese Language Proficiency Test (JLPT) N4, here are some suggestions:

However, before you click on any random link, this article will explain what the Gakushudo N4 book is, why it works, the legal ways to obtain it, and the risks of illegal downloads. We will also provide a roadmap to using this book effectively.

A) Buy the physical book + digital bundle

On Amazon Japan (global shipping) or CDJapan, he could buy the paperback. Some sellers include a unique code to download a watermarked PDF for personal use.

Academia.edu: Tersedia dokumen rangkuman Tata Bahasa N4 yang sering menyertakan materi dari metode Gakushudo.

Unlike the famous Minna no Nihongo or Genki, which are general learning series, Gakushudo is laser-focused on exam strategy. It breaks down complex N4 grammar points (like passive verbs, causative forms, and honorifics) into digestible 2-page spreads.