Ryōbu Shintō receives the Buddhist teaching on karma largely intact, understanding it as a moral law of cause and effect in which intentional actions of body, speech, and mind shape present and future experience, including rebirth. Good and harmful deeds are seen as generating corresponding consequences, and this dynamic is closely tied to ideas of merit and demerit familiar from esoteric Buddhism. At the same time, this karmic causality is not treated as an abstract mechanism but is embedded in a sacred cosmos structured by the two mandalas and populated by buddhas and kami understood in mutual relation.

Within this syncretic vision, karma is interpreted through Shintō categories of purity and pollution. Wrongdoing and unwholesome mental states are not only karmic seeds stretching across lifetimes; they also appear as forms of *tsumi* and *kegare* that distance beings from both kami and buddhas. Karmic obscurations are thus experienced as a kind of spiritual defilement that veils an originally pure nature and obscures the inherent identity with the buddha–kami principle that Ryōbu Shintō affirms.

Because of this, karmic transformation is sought through a combination of esoteric Buddhist and Shintō practices. Mantras, mudrās, and mandalas stand alongside offerings, purification rites, and other forms of kami worship as effective means of purifying karma. Devotion to kami, understood as manifestations or expressions of Buddhist deities, becomes a concrete way to cultivate merit and cleanse defilements, so that karmic burdens are lightened and the relationship with the sacred world is restored.

The ultimate horizon of this karmic work is not merely a favorable rebirth, but a deepened realization of harmony between the realms of buddhas and kami. As karma is purified, the practitioner moves toward an awakening to the original purity of mind and to the non-duality of the Shintō and Buddhist dimensions of reality. In this way, the doctrine of karma in Ryōbu Shintō functions as both a moral framework and a soteriological path, guiding beings toward a state in which the two aspects of the sacred universe are experienced as a unified, living whole.