No method is perfect. Critics of Nihongo no Mori argue that the “Japanese-only” method, while excellent for listening, can be opaque for low-N3 learners attempting N2 prematurely. A learner who has not mastered basic relative clauses will be lost. Furthermore, the free YouTube content, while voluminous, is not organized into a clear syllabus. A student might watch a video on ～まみれ (covered in, e.g., mud) but miss the video on ～だらけ (full of, e.g., mistakes) because the algorithm does not suggest it in order. The paid app solves this with structured paths, but it is a subscription cost that not all learners can afford.