Kakuban was born in Fujitsu-no-shō (Hizen Province, nowadays part of Kashima City, Saga Prefecture) about three hundred years after Shingon Buddhism was first founded by Kūkai (空海).
Born into the Yuasa family (湯浅), allegedly descended from a branch of the Fujiwara clan, he came to be ordained in both the Shingon school of Buddhism and the Kegon school.
Seizan Buddhism also seems to incorporated techniques from the Shingon and Tendai sects including the use of mandala (such as the famous Taima Mandala), and other ascetic practices.
He trained at the Daigo-ji monastery and became a Great Master (Great Acharya) of Shingon Buddhism, and founded Shinnyo-en in 1936.
In modern times, shugendō is practiced mainly by Tendai and Shingon sects, retaining an influence on modern Japanese religion and culture.
During the initial stages of his mission in Japan, the Catholic missionary Francis Xavier was welcomed by the Shingon monks since he used Dainichi, the Japanese name for Vairocana, to designate the Christian God.