A constant thread weaving through Ryōbu Shintō scriptures is the dual genealogy of kami and buddhas—an elegant family tree where Japanese deities and Esoteric Buddhist figures intertwine. On one branch sits the imperial line, sprouting from Amaterasu Ōmikami, then branching down through Ninigi-no-Mikoto to Emperor Jimmu. This mythic descent anchors Shintō authority directly in the sun goddess, reinforcing the emperor’s divine provenance.

Running parallel is the Buddhist lineage centered on Mahāvairocana (Dainichi Nyorai). Tendai and Shingon treatises map a “descent” from Vairocana through successive bodhisattvas and tantric masters, a spiritual pedigree stretching back to India’s great siddhas. In Ryōbu texts, each kami emerges as a suijaku (“traces”) manifestation of a specific Buddha or bodhisattva—Susa-no-O as Avalokiteśvara, for example—so the kami’s family tree roots in both Japanese myth and India’s esoteric soil.

Priestly lineages get equal billing. The Kokugaku revival may steal headlines today, but in medieval Ryōbu circles it was the Tendai and Shingon lineages—Saichō’s and Kūkai’s orders—that held the reins. Shrine priests often traced their initiation back to Kukai’s fireworks of ritual (Daihannyagyō) or Saichō’s Tendai esoterica (Ritsu rituals), claiming unbroken dharma transmission. The Yoshida family, too, carved out its own Shintō pedigree in the 15th century, insisting on hereditary rites distinct from Buddhist clergy.

Recent scholarship—fueled by digital humanities projects at Kyoto University—has spotlighted how these genealogies were more than origin stories. They served as political capital, establishing who had “dibs” on ritual authority. Today’s Shintō–Buddhist dialogues still echo that age-old contest for legitimacy, proving that, when it comes to lineage, history has a long memory.