Sayako Nagai (1977–) is a Japanese novelist and former newspaper journalist. Known for her carefully researched historical fiction, she brings overlooked figures and episodes from Japanese history to life while illuminating enduring aspects of human nature. She won the Nitta Jirō Literary Prize in 2020 for "Akinau Ōkami: Edo Shōnin Sugimoto Mojūrō" and received the 169th Naoki Prize in 2023 for "Kobikichō no Adauchi" ("The Revenge at Kobikichō"). Set around an Edo-period theater district, the novel reconstructs a single revenge incident through multiple perspectives, exploring the interplay of memory, storytelling, and truth.