Rifujin na Magonote is the pen name of a Japanese novelist born on April 3, 1985, in Gifu Prefecture, Japan. He is best known as the original creator of the massively popular fantasy series Mushoku Tensei. The author first developed an interest in storytelling as a child after watching the 1995 animated film Whisper of the Heart. During junior high school, he joined the computer club, where he began writing novels using text editing software and creating picture stories with PowerPoint. After graduating from university in 2007, he started submitting manuscripts to publishers but received no results, which led him to consider giving up on his ambition to become a professional author. Several years later, while reading the web novel Re:Monster, he learned about the user-generated web fiction website Shōsetsuka ni Narō. After reading various serials on the platform, he began publishing his own work there.

From November 2012 to April 2015, Rifujin na Magonote serialized the web novel Mushoku Tensei: Jobless Reincarnation on Shōsetsuka ni Narō. The series became a phenomenon, remaining the number one ranked work on the site from October 2013 to February 2019. The light novel adaptation, illustrated by Shirotaka, was published under Media Factory's MF Books imprint from January 2014 to November 2022, spanning 26 volumes. The series has also spawned numerous manga adaptations, including an ongoing adaptation illustrated by Yuka Fujikawa that began in May 2014, as well as spin-off manga focusing on characters such as Roxy and Eris. Mushoku Tensei has been credited as an influential work in the isekai genre and has consistently ranked highly in the annual Kono Light Novel ga Sugoi! guidebook since 2017. The series has sold over 13 million copies worldwide and has been localized for English audiences by Seven Seas Entertainment. An anime adaptation produced by Studio Bind premiered in January 2021, with a second season airing from July 2023 to July 2024. A third season has been announced. Rifujin na Magonote contributed to the first season of the anime as a supervising director and wrote the screenplay for episode 23. He has also served as the supervising director for the scenario of a game adaptation titled Mushoku Tensei: Game ni Natte mo Honki Dasu.

Beyond Mushoku Tensei, Rifujin na Magonote is the author of Orc Eroica, a light novel series illustrated by Asanagi, which began publication under the Fujimi Fantasia Bunko imprint in 2020 and remains ongoing with five volumes as of the latest available information. His pen name, which combines elements from five previous pseudonyms he used online, translates roughly to Unreasonable Backscratcher. He has cited manga author Satoshi Mizukami, particularly his series Lucifer and the Biscuit Hammer, as a significant influence on his work. He has also drawn inspiration from fantasy video game franchises such as Dragon Quest and Final Fantasy. In interviews, he has discussed how his experiences playing competitive fighting games taught him communication skills, perseverance, and the importance of seeing difficult tasks through to completion, which directly supported him in completing the lengthy web novel serialization of Mushoku Tensei. He is friends with fellow Shōsetsuka ni Narō writers including Tappei Nagatsuki of Re:Zero fame, Natsume Akatsuki of KonoSuba, Kugane Maruyama of Overlord, and Carlo Zen of Saga of Tanya the Evil, with whom he shared a communal chatroom until 2015. Regarding his artistic philosophy, Rifujin na Magonote has stated his commitment to writing the story he wants to tell without compromising to market pressures or reader demands. He has explained his approach to depicting sexuality in his work as aiming for a middle ground between treating it as sacred and as mere pleasure, viewing reproductive activity as a natural and important aspect of being a living creature.