The Buddhist activities in the Kamakura era have long been a theme of discussion. But when we say that the newly introduced Buddhism had reforming energies, we have that specific logic in mind that was elaborated in the doctrine of the Ikkosenshu (一向専修). This was, indeed, the reflection of the aspirations of the lower classes thrown into the turmoil of the disintegration of manorialism, but in the long struggle of ideologies it was defeated. Meanwhile from the upper strata of the society there emerged a system of thought which took the side of the defender of the manorial regime. This was the doctrine of the Honjisuijaku (本地垂迹), that reactionary conception von oben which was intended to arrest the popular agitations von herunter. This struggle of the different views, however, was determined by the various aspects of the particular localities and provides characteristics too complex to be generalized. The object of this article is an attempt to illustrate the process of the struggle in cities and among the Easterners, and to pursue the political significance of the waning of the teaching of Shinran (親鸞) to which posterity has paid homage as the highest among saints.