In the Sanno shinto, it was considered that the deities of Sanno are manifestation of Shakyamuni, and as each of the Chinese characters '山' and '王' consists of three lines and a line going through the three lines, the Sanno shinto worship was taught in connection with the thoughts of the Tendai sect known as Santai Sokuitsu, meaning three forms of truth is originally one thing.
山王神道では山王神は釈迦の垂迹であるとされ、「山」の字も「王」の字も、三本の線とそれを貫く一本の線からなっており、これを天台宗の思想である三諦即一思想と結びつけて説いた。