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.
成立は、隆房の若い時期の習作と考える説（鈴木徳男）や、治承元年（1177年）以降、正治2年（1200年）以前とする説（佐藤恒雄）、文治建久期、遅くとも正治以前とする説（上野順子）などがあり、はっきりしない。