Fuminori Teshima is a Japanese author and original creator, born on March 5, 1981. His name in Japanese is 手島 史詞. Teshima has been active as a writer since at least 2007, with a significant body of work primarily in the light novel format. He is the author of numerous light novel series, many of which were published by Hobby Japan under their HJ Bunko imprint. His earlier works include titles such as the twelve-volume Kageshitsuji Marc Series, which ran from 2008 to 2011, as well as Kenkoku no Jungfrau and Tobenai Chou to Sora no Shachi.

Teshima is best known as the creator of An Archdemon's Dilemma: How to Love Your Elf Bride. This series began as a light novel published by Hobby Japan, with the first volume released on February 1, 2017, featuring illustrations by the artist COMTA. The series, also known by its Japanese title Maō no Ore ga Dorei Erufu o Yome ni Shita ndaga, Dō Medereba Ii?, has been a central work in his bibliography, with eighteen volumes released as of April 2024. The story follows the sorcerer Zagan and his relationship with the elf slave Nephy, blending fantasy and romance. For this series, Teshima is credited as the author of the original story, while COMTA handled the original character design.

The success of the light novel led to multiple adaptations across different media, all of which trace back to Teshima’s original work. A manga adaptation of An Archdemon's Dilemma: How to Love Your Elf Bride, illustrated by Hako Itagaki, began serialization in Hobby Japan’s Comic Fire magazine in February 2018. An anime television series adaptation produced by the studio Brain's Base aired from April to June 2024. Furthermore, the universe expanded with a spin-off manga titled An Archdemon's (Friend's) Dilemma: How to Babysit a Crybaby Knight, for which Teshima is also credited as the original creator, with the story by Momo Futaba and Hako Itagaki.

Beyond his most famous work, Teshima has maintained a steady output as a light novelist. His other series include Ginen no Nanatsu Hime to Nanaka no Ouji, Ignis no Meiyaku Kishi, and Tokyo Ikai no Barista, among many others published between 2011 and 2018. His creative identity is strongly tied to the fantasy genre, often creating stories that involve magic, sorcerers, and mythical beings, with recurring themes of unlikely relationships and domestic life intertwined with fantastical conflict. Teshima’s significance in the industry lies in his consistent production of long-running light novel series that successfully transition into manga and anime, establishing him as a prominent original creator within the Japanese publishing and animation ecosystem.