National Treasures & Important Cultural Properties
of National Institutes for Cultural Heritage, Japan

　　This is a letter written by Saichō (Dengyō Daishi; 767–822), the founder of the Japanese Tendai sect of Buddhism. It is addressed to his most beloved disciple, Taihan (b. 778), who at the time was studying at Takaosanji Temple (present-day Jingoji Temple) in Kyōto with Kūkai (Kōbō Daishi; 774–835), the founder of the Shingon sect in Japan. This is the only extant letter in Saichō’s own hand. It is called the Kyūkakujō because it begins with the phrase, “I have not heard from you in a long time (kyūkaku seion).” The sekitoku means a letter by classical Chinese.
　　On the twenty-third day of eleventh month of Kōnin 4 (813), Saichō wrote a letter to Kūkai asking to borrow the texts Manjusri’s Praises of the Dharma-body, also known as the One Hundred Twenty Lines in Praise of the Buddha, the Square and Round Charts, and the Notes and Commentaries, as well as the Interpretation of the Truth Sutra. In response, however, Kūkai severely criticized Saichō for wanting to study esoteric Buddhism only through texts and refused to lend him the Interpretation of the Truth Sutra. Upon reading this, Saichō wrote Taihan the Kyūkakujō on the twenty-fifth day of the eleventh month, requesting that Taihan ask Kūkai in person the meaning of the Manjusri’s Praises of the Dharma-body, the Square and Round Charts, and the Notes and Commentaries.
　　Previous to this, Saichō had received a poem from Kūkai, to which Saichō intended to compose a poem in response. However, the preface of Kūkai’s poem mentioned the titles of the texts Manjusri’s Praises of the Dharma-body, the Square and Round Charts, and the Notes and Commentaries, all of which were unfamiliar to the Tendai patriarch. Saichō, ever earnest in his dealings, wanted to read these texts himself in order to write an appropriate poetic response. Although he seems to have given up the idea of borrowing the Interpretation of the Truth Sutra, he at least wanted Taihan to ask about the contents of the unknown sources.
　　At this time, Saichō was forty-seven and Kūkai was forty. In the text of the letter, Saichō takes various measures to show courtesy to the younger Kūkai, as in always positioning Kūkai’s title, the Great Esoteric Teacher, at the beginning of a new line. This careful attention to etiquette reflects Saichō1’s sincere character. His handwriting also reveals a high level of sophistication.