The process of Japanese society shifting into a more medieval state can be seen by looking at various pieces of Japanese literature, such as poetry and prose, that were written around the time that this shift is said to have started to happen, specifically in the Heian (794-1185) and Kamakura (1185-1333) periods. Things like war tales, Gunki monogatari, emerged reflecting the tumultuous state of Japan during these times, with the Heike monogatari being one of the most famous pieces; further development of zuihitsu also occurred. This shift into a more medieval state can also be witnessed more clearly when comparing how and why pieces were written during the Heian period of Japan as opposed to how and why they were written during the Kamakura period which followed right after. This can be seen specifically when examining the practices of the composition of things like the imperial anthologies, or chokusenshu, during the Heian and Kamakura periods, that often reflect the social and political realignments that were taking place at the time. Robert N. Huey states two specific things that point to a medievalization process taking place:
(1) Cracks in the homogenous edifice of waka; that is, evidence that differences among poetic groups are so strong that people are willing to “go public” with their disagreements. In other words, waka moves from social expression, about which people in a hierarchical environment are likely to agree, to art, about which people in a more factionalized medieval setting are apt to disagree.
(2) Concomitantly, a move towards privatization and exclusivity. Not only are there poetic schools, but these schools become such discrete entities that normal social bonds (i.e., effected by emperors, retired emperors, other important politicians) cannot bring them together. Naturally, this reflects social and political changes [as well].
Firstly, lets look at the imperial anthologies. In the beginning we have the first three anthologies that are grouped together as the Sandaishuu: the Kokinshu (905), Gosenshu (951), and Shuishu (1006). Both the Kokinshu and Gosenshu were ordered by emperors and compiled by a committee and had a generally agreed upon view about what was considered the appropriate kind of waka for an imperial anthology. Shuishu was, however, ordered by a retired emperor, which started the trend for later on when more retired emperors would have anthologies compiled as well, as opposed to emperors, in a sort of attempt to make a display of their political power in many cases. The first sort of cracks with society leaning towards medievalization begin to show with this, but more so with the Goshuishu (1086) which was ordered by Emperor Shirakawa. Shirakawa very deliberately chose a single compiler, Fujiwara Michitoshi, as opposed to Minamoto Tsunenobu who had expected to receive the commission. This appears to have been entirely political, since Minamoto Tsunenobu was close to a dominant...