The Monshu (門主), or keeper of the gate is a term sometimes used in Japanese Buddhism to denote the head of a monastery, as in the case of Jōdo-shū and Tendai Buddhism, but in the case of the Nishi Hongan-ji sub-sect of Jōdo Shinshū Buddhism, it refers to the spiritual leader of the sect, and direct descendant of its founder Shinran.
The Monshu in Jōdo Shinshū Buddhism was the guardian of Shinran's mausoleum, as well as the head of the sect.
This position was started when the youngest daughter of Shinran, Kakushinni, installed her son as the custodian of the small shrine which held Shinran's image and ashes at Ōtani, in Kyoto.
In time the small shrine grew into what is now the Hongan-ji temples (east and west).
He succeeded his father Sokunyo Shōnin (Ōtani Kōshin, born 1945) on 6 June 2014.