I reached the section dealing with this Heian period work yesterday. The Anthology I am reading just gives a few excerpts from the whole poetical diary but even from that little its clear that its a work of great psychological and emotional depth.
It was written around the end of the 10th Century CE by a figure we have come to know as the mother of Michitsuna and is an example of the diary literature genre 日記文学 of the period. The diary covers the period of the authors life 954-974, 天暦8 to 天延2 (The Era dates Tenryaku 8 to Ten'en 2), and in terms of format is divided into 3 sections consisting of memoir, day to day entry style and a mixed section of poetry and observations/reflections.
It also features several examples of poetry (of remarkable depth and elegance) that are exchanged between the author and her husband Fujiwara no Kane'ie, a noble who had attained the post at court of Captain of the Right Guards. They would have probably been texting each other nowadays...how times change and yet remain the same!
It is often regarded (I have read quite amusing asides by readers of various editions and formats of the work) as a dark and sombre, even depressing piece of literature, but there are also great moments of levity, as well as vivid and detailed description too in the midst of her constant relationship woes. It is really remarkably moving and well worth poring over. It is not entirely clear to me whether this is a 'real' diary or not - perhaps it will never be entirely sure and the work does seem very egocentric almost self-obsessed to the exclusion of other people and events as seperately realised objective figures. Fascinating as an early example of prose fiction still on its newborn tentative fragile legs and significant as the very few works of its kind of any length that has survived pre-Genji Monogatari. The transcriptions are based upon a composite amalgamation of texts and fragments.
There is an interesting article entitled 'Style and Point of View in the Kagero Nikki' - Watanabe Minoru and R.Bowring on JSTOR (From Journal of Japanese Studies Vol.10,No.2 (Summer 1984) which is in turn based upon a translation by Richard Bowring of a chapter of a book by Watanabe Minoru, 'Heiancho Bunshoshi' Tokyo Daigaku Shuppankai 1981 (｢平安朝文章史」東京大学出版会 1981).
Amongst other things the article deals with Watanabes concept of the 'unmediated author' of the Kagero Nikki and a contrasting appraisal of the prose work and poetry as vehicles of expression and degree control of emotions in the Kagero Nikki.
From Watanabe's interesting and at the time (1981) novel appraisal, bringing his skills as a Language history expert and expertise in stylistic analysis to bear on weighing up the artistic merits of the text it would appear that this works position/status in Japanese Literature is a trailblazer (albeit an unconscious one) in early Japanese prose fiction - not entirely successful but certainly a significant precursor if not enabler of greater works to come such as the Genji Monogatari. It is also noteworthy as one of the first works to have been written for its own sake as opposed to having been commissioned by another.