The purpose of this contribution is to clarify “Nichirenism within Nishiren-shū.” Specifically, we focus on Mochizuki Nichiken 望月日謙 （1865–1943）, who served in important roles such as Chief Abbot of the Nichiren-shū, 83rd Archbishop of Minobu-san Kuon-ji 身延山久遠寺 and President of Risshō University. Nichiken interacted with Tanaka Chigaku 田中智学 （1861–1939）, who was the first evangelist of Nichirenism, and Chigaku’s disciple, Yamakawa Chiou 山川智応 （1879–1956）. This had a profound influence on Nichiken, particularly in terms of his theory of national identity. On the other hand, we can see that Nichiken’s viewpoint differed from that of Chigaku about honzon 本尊, the main object of worship, as witnessed in Nichiken’s letter to the Okajima family, lay believers of the Minobu-san Kuon-ji. In addition, Nichiken’s explanation about Nichirenism was slightly different from Chigaku’s beliefs, which leads us to think that they had differing opinions about Nichirenism.
