刀劍神域
Kawahara also writes the "Sword Art Online: Progressive" series, which covers Kirito's adventures on the first few floors of Aincrad. The first volume of "Progressive" was released on October 10, 2012, and eight volumes have been released as of June 10, 2021. The first volume of a light novel series based on "Sword Art Online" titled "Sword Art Online Alternative Gun Gale Online", written by Keiichi Sigsawa with illustrations by Kouhaku Kuroboshi, was published by ASCII Media Works on December 10, 2014. An original 100-page prequel novel to "" written by Kawahara, titled "Hopeful Chant", was released to people who watched the film in Japan during March 4–10, 2017.