The Kumon Reading program is a highly effective approach to developing strong reading comprehension and structural writing skills through materials which cover topics and stories from countries all over the world and a very enriched vocabulary.
Levels 7A-3A are the Early Learner levels, where students gain the necessary sight word base to read simple texts comfortably as well as excellent phonics and decoding skills. For more details about these levels, see here.
Levels 2A-CII are the basic grammar, reading comprehension, and vocabulary development levels, approximately covering the primary grades in the Ontario curriculum, where students become fluent in reading and proficient in basic sentence analysis (nouns/verbs/adjectives/adverbs and subject/predicate/direct object), and working with commonly used verb tenses as well as the passive and active voice. The wide variety of engaging stories used here is mostly fiction.
Levels DI-FII correspond approximately to middle school material in the Ontario curriculum, and incorporate much more non-fiction, as well as more and more advanced vocabulary, reading comprehension, and elements of writing to prepare fully for high school.
Levels G-L correspond approximately to high school material in the Ontario curriculum, exploring high-level reading comprehension, summary, summation, précis, and critical analysis of advanced materials including classical poetry and Shakespeare. The vocabulary level here is extremely high, providing an excellent preparation for success in university and beyond.