Shingon Buddhism arose in the eighth century and remains one of Japan's most important sects, at present numbering some 12 million adherents. As such it is long overdue appropriate coverage. Here, the well-respected Mark Unno illuminates the tantric practice of the Mantra of Light, the most central of Shingon practices, complete with translations and an in-depth exploration of the scholar-monk Myoe Koben, the Mantra of Light's foremost proponent.