Reki Kawahara is a Japanese novelist born on August 17, 1974, in Takasaki, Gunma Prefecture, Japan. He is widely recognized as the original creator of the Sword Art Online and Accel World franchises, both of which began as light novel series before being adapted into various anime, manga, and film projects.

Kawahara originally wrote the first story for Sword Art Online in 2001 as a potential entry for a competition hosted by ASCII Media Works. However, he did not submit it because the manuscript exceeded the contest's page limit. Instead, he chose to publish the story online as a web novel under the pen name Fumio Kunori. Over the following years, he continued to write additional story arcs and side stories for the series on his website.

His professional debut as a published author came with a different series, Accel World. Kawahara entered the first novel of Accel World into ASCII Media Works' 15th Dengeki Novel Prize in 2008, where it won the Grand Prize. The first light novel volume was subsequently published by Dengeki Bunko in February 2009. Following the success of this award, Kawahara republished Sword Art Online as a print light novel series beginning in April 2009.

The popularity of these light novels led to major anime adaptations. An anime television series for Accel World premiered in April 2012, followed by the Sword Art Online anime in July 2012. Both series achieved significant international success, turning Kawahara into one of the most prominent names in contemporary Japanese light novel writing. He has continued to write and publish long-running series, with both Accel World and Sword Art Online comprising over twenty-five volumes each.

Beyond the main series, Kawahara has authored several related works. He writes Sword Art Online: Progressive, a reboot that retells the original Aincrad arc floor by floor. He also created The Isolator, another light novel series that began serialization online in 2004 before being published in print starting in 2014. Additionally, he serves as the original story supervisor for various spin-off series, including Sword Art Online Alternative: Gun Gale Online, written by Keiichi Sigsawa.

Kawahara has been directly involved in the screenwriting for several anime film adaptations of his work. He wrote the screenplay for the 2016 film Accel World: Infinite Burst. He also wrote the screenplay for the 2017 theatrical film Sword Art Online The Movie: Ordinal Scale. For the two-part Sword Art Online Progressive film adaptations, Aria of a Starless Night (2021) and Scherzo of Deep Night (2022), he is credited with the original script and providing screenplay assistance.

A consistent theme throughout Kawahara's work is the exploration of virtual reality, massively multiplayer online games, and the blurring line between digital and real-world identities. Both Sword Art Online and Accel World center on protagonists who navigate complex, game-based virtual environments where the stakes have profound real-world consequences. This focus is drawn from his personal interests, as he has cited the classic computer role-playing game Wizardry as a major source of creative inspiration.