It was previously announced that Reki Kawahara’s Sword Art Online would receive two television anime series this year. The first is the adaptation of the Sword Art Online: Alicization arc from Kawahara’s light novels, the other is based off of Keiichi Sigsawa’s light novel series which serves as a spinoff to the Gun Gale Online arc.
While we do not have a release time frame for Alicization, it was announced that the Gun Gale Online spinoff will premiere during the Spring anime season this April!
MyAnimeList.net describes the story of Sword Art Online Alternative: Gun Gale Online as follows:
Karen Kohiruimaki always felt out of place in the real world. Due to her extreme height, she found it hard to make friends with other girls her age. Everything changes when she’s introduced to VR and Gun Gale Online. In GGO, Karen is free to play the cute, chibi avatar of her dreams! Can Karen find friendship in this bullet-ridden MMO…?