Born in 1201 in Yamato Province. Lamenting the decline of monastic precepts, in 1236 he performed self-ordination at Tōdaiji and moved to Saidaiji to revive Shingon Ritsu. Under the banner of "promoting dharma and benefiting all beings," he revered outcasts and lepers as incarnations of Mañjuśrī, devoting his life to social welfare — distributing food, granting precepts, and establishing medical facilities. During the Mongol invasions of 1281, he performed prayers for national defense at Iwashimizu Hachimangū and Shitennōji at the shogunate's request. He died in 1290 at age ninety and was posthumously titled "Kōshō Bosatsu."

A practical religious leader combining fierce dedication to precept revival with deep compassion for the poor, sick, and outcasts. He granted precepts regardless of status, striving to bring the Buddha's light to society's lowest.

He revived Saidaiji as the headquarters of Shingon Ritsu, building a network of some 1,500 branch temples nationwide. His social welfare work is recognized as pioneering Japanese charity, and his spirit spread to Kamakura through his disciple Ninshō.