[2] Keizan and his disciples are credited with beginning the spread of Sōtō Zen throughout Japan, away from the cloistered monastic practice characteristic of Dōgen's Eihei-ji and towards a more popular religion that appealed to all levels of Japanese society.

He reached the stage of "non-backsliding" while training with Jakuen, and received dharma transmission from Tettsū Gikai at the age of thirty-two, according to his autobiography; he was the first Japanese Zen monk to describe his own life.

By the time of the Meiji Restoration in 1872, they had arrived at a truce, according to the characterization that the Sōtō school followed "the maxims of the founding Ancestor, Dōgen, and the aspirations of the late teacher, Keizan.

(Jiyu-Kennett 2002: 97) Apart from extending the appeal of Sōtō Zen to the rural population, Keizan made efforts to encourage the training of women in Buddhism.

[6] Keizan's veneration of the bodhisattva Guanyin (Kannon, in Japanese)—who is customarily represented as female in East Asian Buddhism—stemmed from or was enhanced by his mother's devotion to her.

[6] Keizan had a nunnery constructed near Yōkō-ji (eventually making Sonin the abbess) and ensured that funds were allocated for its continuing survival (Faure 2000: 42).

This is also a focal point in Dogen’s writing, and both men, as Zen patriarchs, are equally concerned with the training of monks and the selection of successors.