Many learners jump to L6 because L1–L5 review beginner grammar (てある, ておく, てしまう). Do not skip these. They set the tone for how the book handles "transitivity pairs" (自動詞・他動詞).
If you need the full physical textbook or a permanent digital copy, it is available through major retailers: Amazon Japan White Rabbit Japan (OMG Japan) Further Exploration View the detailed Revised Edition Overview chuukyuu e ikou 55 pdf
Whether you secure the official Chuukyuu e Ikou 55 in print or as a legal e-book, follow this 5-step study plan to maximize results: Many learners jump to L6 because L1–L5 review
: 3A Corporation provides free audio files and a teacher's guide PDF on their website. chuukyuu e ikou 55 pdf