Rinzai monk of the Myōshinji sect. He practiced Zen at Tenryūji under Seki Seisetsu, and was the president of Hanazono University from 1949 to 1978, from which he had graduated. In 1982, Mumon became the 639th head of the Rinzai Myōshinji sect. Other titles included the chief priest of Myōshinji Reiun-in, the head priest of Shōfukuji Temple in Kobe, the director of the Zen Culture Research Institute, and the head of the Myōshinji sect.