A characteristic of the Goryū Shintō (御流神道) at Kōyasan in the early modern period is its transmission in conjunction with Yuiitsu Shintō (唯一神道), which was begun by Eisen (英仙, 1666–1745 or later). According to prior research into Eisen’s Yuiitsu Shintō transmission, based on the writings of Banzen (鑁善, 1774–1845 or later) this had been transmitted to him from Yoshikawa Isoku (吉川惟則). However, there is no discussion of this in the primary materials. Accordingly, the author has reconstructed as far as possible the shōgyō (聖教) of Yuiitsu Shintō of that time, based on the manuscripts in Eisen’s own handwriting preserved in the temple where he was the abbot, the former Nikkō-in. As a result, besides the five examples pointed out in prior research, at present the existence of a total of fourteen examples has been confirmed.
Among them, the colophon of the newly discovered Jimyōin text of the Jinpai no yurushi fuda (神拜之許札) confirms that the Yuiitsu Shintō teacher of Eisen was Yasuda Sadamaro (安田貞麿), a disciple of Yoshikawa Koretaru (吉川惟足). In other words, a portion of the Yuiitsu Shintō shōgyō transmitted by Eisen was taught to him by Yasuda Sadamaro, and not Yoshikawa Isoku.
