Within the Tendai tradition, engagement with Ryōbu Shintō unfolded above all in those currents most steeped in esoteric practice and in the cult of the mountain deities. The Sannō Ichijitsu Shintō lineages centered on Mt. Hiei, with their veneration of Sannō Gongen as a kami-Buddha synthesis, became a particularly important locus for this interaction. Here, the language of unity between kami and buddhas found a ritual and doctrinal home, allowing practitioners to move fluidly between shrine and temple without feeling they were crossing a sharp boundary. This was not merely a matter of adding Shintō elements to Buddhism, but of reading both through a single, syncretic lens.

Closely related to this were the Taimitsu, or esoteric Tendai, lineages. These ritual and doctrinal streams, already grounded in mandalas, mantras, and complex visualizations, proved especially receptive to Ryōbu Shintō teachings. By integrating kami into the existing esoteric pantheon and symbolic universe, Taimitsu lineages could interpret local deities as manifestations within a broader esoteric cosmos. In such settings, Ryōbu Shintō did not stand apart as a separate system so much as it permeated the living practice of Tendai esotericism.

More broadly, the Tendai temple-shrine complexes on Mt. Hiei and their affiliated clergy formed the primary milieu in which this synthesis took root. The interplay of Sannō cult doctrines with esoteric ritual created a distinctive spiritual atmosphere, one in which the boundaries between Shintō and Buddhism were deliberately softened. For practitioners shaped by these lineages, Ryōbu Shintō functioned as a hermeneutic key, enabling a reading of the world in which kami and buddhas were seen as different faces of a single, all-encompassing sacred reality.