Kiyoi Kagaya (born 1980) is a Japanese novelist and picture-book author. Born in Hanamaki, Iwate Prefecture, she graduated from Tohoku University. She made her literary debut after winning the 2026 Japan Fantasy Novel Award with "Ten o Shu ni Some: Otogizoshi Ibun." Under the pen name Sakaki Yayoi, she has also published picture books and worked as an illustrator, creating works distinguished by their imaginative storytelling. Her best-known novel, "Shuten no Miyako," a revised and expanded version of her award-winning manuscript, reimagines the legend of Shuten Dōji while exploring themes of coexistence with those perceived as different and the nature of justice.