Monkan (1278 - November 29, 1357) was a priest who lived from the Kamakura period to the period of the Northern and Southern Courts. Ono Sojo. Shuon, Koshin. He was the head priest of Daigo-ji Temple.
In 1302, he was a priest of the Risshu sect at Hannya-ji Temple and learned Shingonritsu at temples related to Saidai-ji Temple (Nara City) such as Hojo Joraku-ji Temple in Harima Province (Kakogawa City, Hyogo Prefecture) and Kasayama Chikuzan-ji Temple in Yamato Province (Kasa, Sakurai City, Nara Prefecture). In 1316, he was given Kanjo (conferred the basic precepts and mystic teachings of esoteric Buddhism) by Dojun of Hoonin, Daigo-ji Temple. He was also known as a priest of Tachikawa school (Mikkyo, Esoteric Buddhism), the Shingon sect, which was considered as a heretical religion, and he was a priest who renounced the world and relieved the poor with Enkan (Echin). He was taken into confidence by Emperor Godaigo and assumed the role of the head priest of Daigo-ji Temple and Betto (the superior of a temple) of Tenno-ji Temple. In 1324, he made the statue of Monju Bosatsu (Manjusri Bodhisattva associated with wisdom, doctrine and awareness) at Hannya-ji Temple and it was brought to light that he had implemented rituals to attempt to destroy the Kamakura Shogunate, by FUJIWARA no Kishi, chugu (the second consort of an emperor) of Godaigo from 1326, so he was arrested in 1331 and was sentenced to deportation to Io-jima Island (Kagoshima Prefecture). When the Kamakura Shogunate was subverted after the Genko Incident in 1333, he went back to Kyoto, and he also moved to Yoshino in attendance of Godaigo and became Chief Abbot of To-ji Temple and daisojo (a Buddhist priest of the highest order). He died at Kongo-ji Temple on Mt. Amano in Kawachi Province (Kawachinagano City, Osaka Prefecture) at the age of 80.