Ryōbu Shintō approaches the relationship between kami and Buddhist deities through the doctrine of *honji suijaku*, “original ground and manifest traces.” In this vision, Buddhas and bodhisattvas are the original ground, the universal and ultimate forms, while the kami are their compassionate manifestations, appearing in local, culturally familiar guise. The kami are not dismissed as false; rather, they are reinterpreted as provisional, localized expressions of the same enlightened reality that the Buddhist deities embody. This creates a hierarchical yet continuous sacred order, in which devotion to a shrine kami is simultaneously a way of relating to a deeper Buddhist source. The language of “traces” suggests that the kami are tailored revelations, adapted to the capacities and needs of beings in a particular land.

Within this framework, specific correspondences are drawn between prominent kami and central Buddhist figures. Amaterasu Ōmikami is identified with Dainichi Nyorai (Mahāvairocana), the cosmic Buddha at the heart of esoteric Buddhism, while Hachiman is interpreted as a bodhisattva or linked to figures such as Amida. Other kami, such as Inari, are associated with particular Buddhist deities like Dakini-ten. These pairings are not merely speculative; they are embedded in ritual texts, doctrinal writings, and visual materials that function almost like mandalas, mapping the Japanese pantheon onto an esoteric Buddhist cosmos. Through such identifications, the many gods of the shrines become different doors into a single, integrated sacred reality.

The esoteric cosmology of Shingon Buddhism provides an additional layer of reconciliation through the symbolism of the two mandalas, which Ryōbu (“two departments”) Shintō adopts. The Taizōkai (Womb Realm) mandala is associated with nurturing, this-worldly functions, while the Kongōkai (Diamond Realm) mandala emphasizes wisdom and the unshakable ground of enlightenment. Kami are situated within these mandalic structures as accessible forms of Buddhist enlightenment, their roles and attributes echoing the functions of the deities with whom they are paired. In this way, the visible world of shrines and myths is read as a patterned reflection of an invisible, esoteric order.

This doctrinal synthesis is carried into myth, space, and practice. Narratives from early Shinto texts are allegorically reread as symbolic expressions of Buddha-activity, so that the deeds of the kami reveal, beneath their surface, the workings of universal compassion and wisdom. Shrine precincts themselves are interpreted as terrestrial counterparts of esoteric mandalas, with architecture, processions, and offerings overlaid with Shingon symbolism. Rituals at shrines may employ mantras, mudrās, and visualizations drawn from esoteric Buddhism, allowing the same act of worship to be understood simultaneously as honoring a kami and invoking the corresponding Buddha or bodhisattva. In this layered vision, the path through the local and particular becomes a path into the universal and absolute, without forcing a stark choice between Shinto and Buddhism.