Whether you have six months or six weeks, this PDF, used correctly, can carry you from absolute beginner to JLPT N5 pass in record time.
Buy the physical book (~$15 USD) or official e-book. Then, use free grammar summary PDFs from study blogs as review sheets alongside the book. nihongo challenge n5 grammar pdf
The PDF has a 2-page quiz every 5 days. Many learners think, "I’ll come back to it." They never do. Whether you have six months or six weeks,