Moto'o Nakanishi is a Japanese author known for creating the fantasy novel series Sword of the Demon Hunter: Kijin Gentōshō. He is a relatively new writer who began his career by publishing stories online. He first serialized his work on the user-generated novel website Arcadia from January 2013 to May 2016, later moving it to the Shōsetsuka ni Narō platform from December 2015 to October 2016. His growing popularity led to a print publication deal, and the series was officially acquired by the publisher Futabasha. The first volume of the light novel was released on June 21, 2019, featuring illustrations by the artist Tamaki. Nakanishi is based in Aichi Prefecture. His interests in folklore and the works of authors such as Kyōgoku Natsuhiko and Yanagita Kunio have influenced his writing. He also practiced kendo in high school, and this background in swordsmanship informs his action scenes and the themes of his work.

Nakanishi's primary and most notable original work is Sword of the Demon Hunter: Kijin Gentōshō. The series is a historical fantasy that spans several centuries, beginning in the Edo period. The story follows a young warrior named Jinta, the guardian of a shrine maiden, who encounters a demon that speaks of the far future and a great threat. This event sets him on a journey through time across the Meiji, Taishō, Shōwa, and Heisei periods, as he questions his destiny and the reason he wields a sword. The light novel series has been commercially successful, with over 230,000 copies in circulation. As of November 2023, fourteen volumes have been published by Futabasha.

The success of the original novels has led to several adaptations. A manga adaptation, illustrated by Yū Satomi, began serialization in Futabasha's Action Comics imprint on September 9, 2021. As of March 2025, eight tankōbon volumes of the manga have been released. Both the light novel series and the manga adaptation are licensed for English release in North America by Seven Seas Entertainment. An anime television series adaptation was announced in September 2021. Produced by Yokohama Animation Laboratory and directed by Kazuya Aiura, the anime premiered on March 31, 2025, on Tokyo MX and other networks, and is scheduled to run for two consecutive cours. The series is distributed in North America by Sentai Filmworks on the HIDIVE streaming platform.

Moto'o Nakanishi represents a generation of authors who have successfully transitioned from online self-publishing to traditional media, with his work achieving a significant multimedia franchise status including a light novel series, manga, and anime adaptation.