Oomoto's history begins on the night of the Lunar New Year in 1892, when the Foundress Nao Deguchi had the first of a series of divine revelations which form the basis of Oomoto.

Nao, a 56-year old woman from the poverty-stricken farmland of Ayabe, northwest of Kyoto, at first could not fully understand her own automatic writings, which are known as the Ofudesaki "From the Tip of the Brush".

However, in 1899, the young mystic Onisaburo joined her small band of believers. Onisaburo, possessed of strong spiritual powers, artistic creativity, and immense energy, was to become one of the most charismatic figures in Japanese religious and intellectual thought of the 20th century.

In 1900, he married Nao's daughter Sumiko and over the next decades the basic outlines of Oomoto's teachings took shape under his guidance.