On the other hand, poetry in the Japanese style flourished uniformly in Kyōto, unaffected by the vicissitudes of the times or the decline of the imperial power. Collections of verses were made from time to time and published by imperial direction, among which the "_Shin-Kokinshū_" contains stanzas constructed with so great skill that it remained a model for the poets of all subsequent generations. In Kamakura, also, the Shōgun Sanetomo was an accomplished writer of Japanese poetry. The grace and polish of his songs in the old-time style, as well as the _verve_ and spirit of their sentiments, reflecting truly the mood of his era, find no parallel in the poetry subsequent to the Nara epoch. Indeed, owing to the great popularity of Japanese poetry in those days, people began for the first time to study it under teachers. Thus there came into vogue men who made a business of giving instruction in the art of poetry, the profession being transmitted from generation to generation in the same family. The result was that canons of style and tricks of composition peculiar to special schools of teachers became more or less binding upon students of those schools, inevitable injury being done to originality and vigor. To these circumstances may be attributed a gradual decline of real poetic ability. Hardly less instructive is the change that overtook the nation's greatest religion, Buddhism. It will be remembered that during the Hei-an epoch, two Buddhist sects, the Tendai, founded by Saichō, and the Shingon, by Kūkai, were incomparably the most influential, all others being more or less in a state of decline. But toward the close of the epoch, some priests, as already related, began to take more interest in military affairs than in religious functions. Yoritomo, when he came into power, interdicted the use of arms by priests, and encouraged them to devote their attention entirely to literature. The prestige of the Tendai and the Shingon suffered from these events, and as their doctrines, being far too recondite and lofty to be comprehended by the uninitiated, had never satisfied the bulk of the people, there began to appear, during the Kamakura epoch, priests who taught a form of the faith radically different from the others but eminently suited to the spiritual tone of the new age. This was the Zen sect, introduced in its various branches from China. It at once attracted men of simple and robust habits by its remarkably vigorous and effective method of enlightenment and the great practical value of the latter for the men of the world in those days of continual fluctuations of fortune. Hōjō Tokiyori and Tokimune, as well as many a great warrior, besides some emperors, became ardent patrons of the sect, which consequently attained prominent popularity among the military men at Kamakura, and developed widespread influence. Its temples, Kenchō-ji and Engaku-ji, at Kamakura, stood on an equal footing with the Kennin-ji and Tōfuku-ji of Kyōto.