Roei Hyakushu (朗詠百首)
The Roei Hyakushu (a hundred medieval Japanese court songs) is a set of waka written while keeping with a theme set by using verses in various anthologies like the Wakan Roei Shu (Collection of Japanese and Chinese Court Songs).
Although the manuscript notes at the end of the book state that the author of Roei Hyakushu is allegedly FUJIWARA no Ietaka (Junii [Junior Second Rank]), studies on the subject have progressed in recent years, and it is virtually certain that the author was FUJIWARA no Takafusa (1148 – 1209). As for when the Roei Hyakushu was completed, there are various opinions, including that it was an etude made by the young Takafusa (opinion offered by Tokuo SUZUKI), that it was finished after 1177 and before 1200 (opinion offered by Tsuneo SATO) and that it was completed between 1185 and 1198, or before 1199 at the latest (opinion offered by Junko UENO), but the real date remains inconclusive. At the very least, it is highly probable that Roei Hyakushu was completed prior to 1199.