Kanbun (漢文?, "Chinese writing"), a method of annotating Classical Chinese so that it can be read in Japanese, was used from the Heian period to the mid-20th century. Much Japanese literature was written in this style, and it was the general writing style for official and intellectual works throughout the period. As a result, Sino-Japanese vocabulary makes up a large portion of the Japanese lexicon, and much classical Chinese literature is accessible to Japanese readers in some semblance of the original. The corresponding system in Korean is gugyeol (口訣/구결).
The Japanese writing system originated through adoption and adaptation of Written Chinese. Japan's oldest books (e.g., Nihon Shoki) and dictionaries (e.g., Tenrei Banshō Meigi and Wamyō Ruijushō) were written in kanbun. Other Japanese literary genres have parallels; the Kaifūsō is the oldest collection of Kanshi (漢詩?, "Han/Chinese poetry") "Chinese poetry composed by Japanese poets". Burton Watson's (1975, 1976) English translations of kanbun compositions provide a good introduction to this literary field.