Myogaku is considered to have compiled a treatise explaining the pronunciations and meanings of kanji for the "Hoke-kyo" (the Lotus Sutra), in which he categorized Japanese pronunciations of kanji with consonants and vowels at the end of syllables in Chinese and made such distinctions as those between the symbols for "u" and "ug" for sequential voicing.
また『法華経』の音義を編したかと考えられ、漢字音を韻尾音によって独自の範疇を設け、独特な反切、uとugの区別、連濁などの符号の記述などが見られる。