The provided sources lack concrete details about Sei Shōnagon's portrayal in the anime Chōyaku Hyakunin Isshu: Uta Koi. These materials focus instead on the historical figure—her authorship of The Pillow Book, her role in the Heian court, and her rivalry with Murasaki Shikibu—as well as her depictions in other media like Fate/Grand Order and the NHK drama Dear Radiance. References to Uta Koi identify Sei Shōnagon as a character but omit specifics regarding her background, story arc, or development within the series.