Training for the Shingon priesthood unfolds as a carefully structured path grounded in the master–disciple relationship and the life of a temple. A candidate first establishes a connection with a Shingon temple and a qualified teacher, then receives ordination and precepts, often accompanied by shaving the head and adopting a priestly lifestyle. This initial step marks formal entrance into religious life and is followed by foundational study of Buddhist doctrine, Shingon teachings, chanting, liturgy, and temple etiquette. Formal Buddhist studies at seminaries or universities may also be required, including work with classical religious texts. Throughout this stage, the emphasis remains on both ethical formation and immersion in the living tradition of the temple.

After this foundation, the heart of Shingon formation lies in esoteric training and initiation. Through abhiṣeka (kanjō), the candidate is ritually introduced to the Two Mandalas—the Womb Realm and the Diamond Realm—and receives transmission of specific esoteric teachings. This includes learning mantras, mudrās, and visualizations, often framed as mastery of the “Three Mysteries” of body, speech, and mind. Intensive residential courses or retreat-style training at major centers such as Kōyasan deepen this practice, focusing on ritual performance, meditation, and the use of mandalas and ritual instruments. Over time, further empowerments and transmissions authorize the priest to perform more complex rites and, eventually, to guide others.

Alongside esoteric practice, there is a steady cultivation of practical and pastoral competence. Priests-in-training learn to conduct funerals, memorial services, seasonal observances, and fire rituals, as well as to manage temple affairs and serve the surrounding community. This dimension of training underscores that Shingon priesthood is not only contemplative but also deeply engaged with the needs of lay followers. Advanced certification involves demonstrating proficiency in complex ritual procedures, completing intensive retreats, and receiving formal recognition from senior clergy. When a practitioner is acknowledged as an ajari (ācārya), this signifies the capacity to independently perform major esoteric rituals and, in some cases, to confer certain initiations, though ongoing study and practice continue throughout the priest’s life.