Ichinyoin Nichijū 一如院日重 was a Buddhist priest active mainly in Kyoto from the Azuchi-Momoyama to the Edo period. One of the characteristics of Nichijū’s academic studies that contributed to the formation of his doctrinal thought was his wide-ranging study of both Buddhist and non-Buddhist texts. In particular, when we focus on the study of Shintō among his studies of non-Buddhist texts, we cannot overlook the fact that Nichijū received instruction on Shintō from his teacher, Busshin’in Nichikō 仏心院日珖.
Based on the Shintō dōitsu kanmishō 神道同一鹹味抄, presented in lecture form by Nichikō and transcribed by Nichijū, which is said to be a commentary on the “Jindai” 神代 volume of the Nihon shoki, I first explore the publication of the book. Next, Nichijū’s Shintō studies are examined in part by presenting the volumes of this book and the period, place, and content of the lectures contained in each volume.
The results of the examination confirm that the Shintō dōitsu kanmishō is a record of the 28 lectures given at Chōmyō-ji 頂妙寺, Kyoto, from May 1 to 28, 1590, with a total of 278 lectures, based on the Nihon shoki’s “Jindai” scroll lectures, the Sanjūbanjin 三十番神, and the transmission from Yoshida Kanetomo 吉田兼倶.
