4. Development of the Annual Change System of Each Head Priest in the Five Temples of Soji-ji (A New Approach to the Historical Research on Keizan-Zen and the Soto-Zen Sect in Japan. (A Commemorative Symposium on the Occasion of the Eightieth Anniversary of Soji-Gakuen established in 1925 and of the Tenth Anniversary of Our Institute established in 1995))