When does Sword Art Online series return?

Sword Art Online is a Japanese light novel series written by Reki Kawahara and illustrated by abec. The series takes place in the then-near future and focuses on protagonists Kazuto "Kirito" Kirigaya and Asuna Yuuki as they play through various virtual reality MMORPG worlds. Six video games based on the series have been released for multiple consoles. The light novels and the manga adaptations have been licensed for release in North America by Yen Press.