Within the diaries…there will be occasional moments when one senses a contrast in moving from poem to prose to poem, but the contrast is surely no greater than that from aria to recitative to aria, and it is usually less. One reason for such smoothness of movement between different literary modes is that the Japanese are so given, or were so given, to responding with poetry that there is a naturalness and integrity in combining the modes. Another reason is that the diary prose itself, through art, shades off from fact at one side of the narrow margin to fiction on the other side. When art is made to seem natural, or when the actual is rendered into full art, the margin becomes less important than the achievement.
—Earl Miner, Japanese Poetic Diaries (U. of California Press, 1969)