[3] By 1618, he had completed a series of instructional materials on the Japanese language in the form of conversations involving Koreans travelling to Japan for business or diplomacy.

[4] The work was published in 10 fascicles in 1676, when it was adopted as the official textbook for teaching Japanese, replacing 14 out-dated titles.

[4] The Japanese text is written in large hiragana, with a phonetic transcription in Hangul on the right and followed by a translation in Korean mixed script.

[6] It contains the same conversations and Korean translation as the original, but the Japanese text was updated to reflect the colloquial language of the time.

[7] Copies of this edition are held in the Seoul National University Library, the Tōyō Bunko and the Eihei Temple.