Kukai travelled to China in the early Heian period to study Esoteric Buddhism from the master Huiguo, and returned to establish the Shingon Buddhist sect in Japan. The commentary from which this fragment comes is an Esoteric Buddhist interpretation of an earlier commentary of the Diamond Sutra by the Chinese monk Ijing(635-713). When originally composed by Kukai following his return from China around 813, the full commentary was in the form of a handscroll, but the scroll was cut into sections at some point several hundred years ago. The surviving sections show annotations and erasures, indicating that this was a draft copy. Though written in the cursive "grass style" of calligraphy, the distinct characters remain unlinked. Among examples of Kukai's calligraphy, this excellent work displays the mellowness of his cursive writing style.