Buddhism begins to spread, despite such machinations, throughout Japan during the ensuing Heian period (794-1185) primarily through two major esoteric sects, Tendai (Heavenly Terrace) and Shingon (True Word).

Tendai originated in China and is based on the Lotus Sutra.

Shingon is an indigenous sect with close affiliations to original Indian, Tibetan, and Chinese Buddhist thought founded by Kukai (also called Kobo Daishi), who greatly impresses the emperors following Emperor Kanmu (782-806) and generations of Japanese, not only with his holiness, but also with his poetry, calligraphy, painting, and sculpture.

Kanmu himself is a notable patron of the otherworldly Tendai sect, which will rise to great power over the ensuing centuries.

A close relationship develops between the Tendai monastery complex on Mount Hiei and the imperial court in its new capital at the foot of the mountain and, as a result, Tendai emphasizes great reverence for the emperor and the nation.