Since the Edo period, the Komachizuka Sutra Mounds in the hills near the Geku of Ise Shrine has been famous as a site from which many sutras written on roof tiles were excavated. However, due to such a reputation, its archaeological finds were scattered and lost from early on.
The roof tile sutras possessed by different organizations include Lotus Sutra, Sutra of Innumerable Meanings, Samantabhadra Contemplation Sutra, Mahavairocana Sutra, Vajrasekhara Sutra, Susiddhikara Sutra, Heart Sutra, Amitabha Sutra and Prajnaparamitanaya Sutra. It is said that over 420 roof tile sutras were buried.
The roof tile sutras were created in the hope that sutras would be maintained without decay and passed down to the future generations until 5.67 billion years later when Maitreya comes to save us. This is why a solid material like a roof tile was selected. The roof tile sutras were actively produced centering on the western part of Japan during the eleventh to twelfth centuries when people were deeply concerned about the coming of the Age of Dharma Decline.
The ceramic halos, lotus pedestals, bases and Gorinto (five-sectioned pagoda) were buried together with the sutras in the sutra mounds. Sanskrit characters are engraved on the ceramic halo: While the larger one represents Mahavairocana Tathagata Hojin Shingon in the Taizokai (Womb World), the smaller ones represent Hoharamitsu, Kongoki, Kongoman, Kongoka, Kongobu, Kongoho, Kongori, Kongoin and Kongogo Bodhisattvas.
The inscriptions show that these artifacts were created from May to July 1174 initiated by Seikan and Junsei, the priests of Mankakuji Temple and sponsored by Watarai Josho and Shunsho, the Shinto priests, of Geku. Since the roof tile sutras include more than one sutra of esoteric Buddhism and accompany esoteric relics, such as ceramic halos, they also provide some materials on the religious background behind the construction of sutra mounds.