[In his introduction (written in 1921) to the Wakameda translation of the Kokinshu, Kobayashi advances several reasons why shorter Japanese poems, such as those found in the Kokinshu, became far more popular than longer forms of verse.]

The Kokinshu or Poems Ancient and Modern was published as is seen in its Preface, in the fifth year of Yengi in the reign of the Emperor Daigo, viz., in the year 905 A.D., and fifteen years after the founding of Oxford University. This collection of one thousand poems was selected from those which had been composed during a period of two hundred years after the beginning of the Nara period, with the intention of showing models to those who wished to compose verses. It was edited by order of the Emperor Daigo, the Editors being four of the greatest poets of that day. They were Ki no Tsurayuki, Ki no Tomonori, Ochikochi no Mitsune and Mibu no Tadamine. This was the first time that Japanese poems were edited by order of an emperor; and in the course of three hundred years from this time down to the first stage of the Kamakura period such work was often undertaken. Of all these four poets, the most excellent was Ochikochi no Mitsune, but the most learned and highest in position was Ki no Tsurayuki. He became chief Editor and wrote the Preface to this collection. In addition, another Preface was written in Chinese by Ki no Yoshimochi, but being nothing but a translation of Tsurayuki's Preface, it was not important.

The first collection of typical poems in Japan is the Manyoshui, which appeared towards the close of the Nara period; and the Kokinshu is the second in age. The Manyoshiu exhibits the features of the verse in the Nara period whilst the characteristics of the poetry in the Heian period are clearly shown in the Kokinshu. Most of the Manyoshiu poems are simple in diction and express the thoughts direct from both heart and mind, while the Kokinshu poems are generally elegant and graceful in thought. Though the Kokinshu contains some of the poems composed in the Nara period, yet they do not signify the features of that day. This is not surprising for the Kokinshu was originally intended to show models to those who wished to compose verses. There have been many changes in the methods of composing Japanese poetry since these days; but generally speaking, the Kokinshu had been looked upon as a model collection of poems for hundreds of years. Therefore it is most important for those who wish to know Japanese poetry.

The Emperor Daigo was an excellent versifier—nay, and many other Japanese Emperors excelled in poetry. Before founding the capital at Kashiwara, the first Emperor Jimmu subjugated the natives in the neighbourhood: on that occasion he himself composed a song with which he encouraged his men. This poem is mentioned in the ancient history of Japan and handed down to posterity. (It may be called an old song, for it was composed in 662 B.C.) Many of the other emperors, the princes and the court officials composed poetry. And there were some peasants and huntsmen who were fond of composing verse. In such ancient days, of course, they used no special art in making poems, but sang what they actually thought. So these poems have little or no poetical merit, but the elegancy of national spirits can be traced up to such an ancient age. In days of yore, there was little strict distinction between the high and low. Some emperors were of so plebeian taste that when they went out hunting they often talked in verse with peasants. When Chinese learning was imported in abundance and people imitated Chinese institutions troublesome ceremonies arose by degrees and the distinction between the high and low began to assert itself. In the Heian period the emperors and court officials were called "kumo-no-uwabito" or "men above clouds." This was contrary to the intrinsic national traits of Japan, which were simplicity and homeliness, with both of which the emperors treated their people generally. These good qualities later revived among the samurai: the so-called spirit of the samurai was merely the revival of the national traits of the Japanese nation. It will be most interesting to study these national traits by means of Japanese poetry.

The art of composing poetry gradually made progress age after age, until at last many true poets appeared in the Nara period. While the capital of Nara was growing prosperous, art and literature were making great progress; whilst amidst the beautiful fields and mountains splendid edifices arose and the sound of music heard, and those who viewed the moon and blossom and composed poems became more numerous than before.

Japan is a land of scenic beauty. Among the rest, the mountains and rivers at Nara and in its vicinity are like pictures: the sky is blue and clear, the air gentle, the blossoms beautiful, and the birds sing merrily. The Japanese people who dwelt in this atmosphere were specially familiar with nature. They did not look on nature as an external world, but as their intimate friend. It seemed to them as if rivers and mountains had souls of their own, and these souls had communion with them. No wonder that poetry made progress among these people. If we turn over the pages of the Manyoshiu, we shall find many valuable poems even in the minor poets, not to speak of Kakinomoto no Hitomaro, Yamabe no Akahito, Yamakami no Okura and Otomo no Yakamochi.

The most notable poems in the Manyoshiu are the longer poems. The versification of old days had no definite rules, and the length of a poem was not limited. But towards the Nara period poetry was divided into two classes, longer and shorter poems. The shorter poem consists of thirty-one syllables, while the longer poem consists of stanzas with twelve syllables. A shorter poem will be sufficient to express a bit of thought, but many words will be needed to convey complicated thoughts. So Hitomaro and many other poets spent their energy chiefly on the longer poem. Of course, they composed many excellent shorter poems, but if the longer poems were withdrawn from the Manyoshiu, it would lose nine-tenths of its merit. Notwithstanding, in the Heian period the longer poem was completely neglected and all poets paid their full attention to the shorter poem. And the word uta has come to mean the shorter poem. It was many, many years after that Kamo no Mabuchi appeared and took pains to revive the longer poem.

There are many reasons for the decay of the longer poem and the shorter poem alone flourished. The first reason is that those who composed poems had become devoid of ideas. It was in the reign of the Emperor Kammu, who was a very able man, that the capital was transferred from Nara to Kyoto. He adopted various methods to make more flourishing the intercourse with China and develop the resources of the eastern part of Japan. It was probably with this object that he transferred the capital to Kyoto. And whenever he had time to spare, the Emperor would go out hunting with his attendants and range over hill and dale. In a word, he was a very plebeian and gallant monarch. However, as some mediocre rulers followed him, the excellent enterprises on the part of the Emperor Kammu ceased, and the Fujiwara family assumed the reins of government. No one, however capable he might be, was appointed to a high office unless he was of the Fujiwara family. They took pains only to increase the prosperity of their family and took negative measures in all other ways. As things went on in this state for a considerable length of time, nobody thought of promoting the national prosperity; and there were few spirited and ambitious men. An indolent atmosphere reigned over all Kyoto. All the rulers grew too self-interested to think of the welfare of the people, who groaned only under the pressure of life and had no time to think of other things. Thus poetry was appreciated only by the court officials, few of whom had great thoughts. So it naturally followed that there was no need of composing long poems. In order to express what they thought the shorter poem was sufficient; for there was no great thinker or poet who wanted a longer form of poetry in which to convey his thoughts.

The second reason is that stress began to be laid on the art of composing poetry. As we have just stated, the Fujiwara family, who had become politically powerful, became luxurious too. They gave little heed to the affairs of state, but whiled away their days, giving banquets in pretence of moon or flower viewing. Their adherents were always present at these feasts and bent upon humouring them. The most refined amusement in such a sumptuous life was verse composing; and they often held uta-awase or poetical competitions. At this meeting the verse-composers were divided into two parties, and composed poems on a given theme. These poems were judged by an umpire. When one of these bards turned out the victor, his or her fame was known throughout the court and could often rise to a higher position or rank. These competitions were so intense that some of the competitors actually died from despair. In such ages, it is natural, poetry became rhetorically excellent rather than in thought. And it is inevitable in such an age that the manners between men and women at Court became corrupt, and that they openly talked of intrigues or amours. Lovers composed poems and thus expressed their hearts to each other; and they took great pains to compose verse, for change frequently arose in their love-relation according to the adroitness or clumsiness of the poems. As stress was chiefly laid on art, it would be difficult to adorn a long poem with exquisite epithets. Thus the shorter form of poetry had come in vogue.

The third reason is that Chinese literature had come to be studied. Chinese books had been imported in the Nara period and became to be read by degrees. And in the Heian period greater grew the number of those who wrote in Chinese prose and verse. Though none of them equalled the Chinese writers, yet those who composed Chinese poems and writings were greatly respected. Consequently, smaller became the number of those who took pains to compose the longer verse.

The fourth reason is that prose had made progress. Japanese prose in the Nara period, compared with poetry, was in a crude condition; but, as Chinese literature was more studied, the more smooth and correct prose became. Poetry became a means of expressing a bit of thought.

For these reasons the longer form of verse had gone downhill. None of the longer poems in the Kokinshu are excellent. This phenomenon was surely a hitch in the development of Japanese poetry; but the shorter verse had made great progress, that is to say, various complicated thoughts are contained in only thirty-one syllables. Few of the Manyoshiu poems equal in this point.

The Kokinshu consists of twenty volumes or parts. Of these volumes, six are the Poems of the Four Seasons and five the Poems of Love. These eleven are thought the most important in the collection. The Kokinshu is a small collection of one thousand poems; but those who study this book minutely will find various suggestions as regards the transition of Japanese thoughts.