You’re getting not one, but two new anime seasons of Sword Art Online!
Just like how a new season of A Certain Magical Index was revealed, Dengeki Bunko also announced details for two more anime seasons of Sword Art Online. The first of the two announced will be adapting the next arc in the main light novel series called Alicization. Alicization is SAO’s longest arc to date, spanning 10 volumes compared to the usual 2-3 that the previous arcs had. In terms of where it starts it’s from volume 9 all the way to 18.
The anime will bring back voice actors Yoshitsugu Matsuoka as Kirito and Haruka Tomatsu as Asuna respectively, as well as introducing Ai Kayano as Alice, and Nobunaga Shimazaki as Eugeo.
The second of the two announced will be adapting a spin-off light novel series called Alternative: Gun Gale Online. This series ran for 5 volumes since December 2014 and it’s quite the surprise to see an adaptation for this particular storyline. Voice actors have been announced for this anime adaptation; with Tomori Kusunoki as Llenn, Yōko Hikasa as Pitohui, Kazuyuki Okitsu as M, and Chinatsu Akasaki as Fukaziroh.
It’s also worth pointing out that there is an upcoming game called Sword Art Online: Fatal Bullet that will be adapting the Gun Gale Online arc from a different what-if perspective (as the game’s story went a different direction since Hollow Fragment). Alternative Gun Gale Online’s Llenn will joining the roster as a playable character.
Sword Art Online does have other spin-off or re-imagining novels including Progressive (which remakes the Aincrad storyline in more detail) and Material Edition which are a bunch of side stories. Yen Press have licensed a number of Sword Art Online properties including the light novels, which are available in digital and in print.