Among the six works authored by the representative monks of the Buddhist schools of Japan in the Tenchō era (824–833), the Himitsu mandara jūjūshin ron (秘密曼荼羅十住心論) of Kūkai (空海, 774–835) and the Kegon ichijō kaishin ron (華厳一乗開心論) of Fuki (普幾, dates unknown) are extant.
The Sŏk mahayŏn non (釋摩訶衍論), imported to Japan by Kaimyō (戒明, dates unknown) of Daian-ji, had been pronounced an apocryphal work by the Monjō Hakase of the time, Ōmine no Mifune Mahito (淡海三船眞人, 722–785). As a historical development, it is well known that Kūkai made significant reference to this text in constructing the thought of Shingon Esoteric Buddhism.
Kūkai took Huayan thought into account in his discussion concerning the development of bodhicitta in the ninth abode of mind in his Himitsu mandara jūjūshin ron. In his Kegon ichijō kaishin ron Fuki relied on Huiyuan’s (慧苑, dates unknown) Xu Huayan lüeshu kanding ji (続華厳略疏刊定記), along with utilizing the Sŏk mahayŏn non for evidence. Those passages conform with Kūkai’s own exposition of Huayan thought, and it is possible to make some conjecture into the content with which Kūkai was concerned. In this report the author shall demonstrate the differences in the interpretations of the Sŏk mahayŏn non of Kūkai and Fuki.