The official site for Key’s Rewrite visual novel series recently kicked off a countdown, building up to the announcement of a new project. There’s currently no additional information, but we won’t have to wait long, because publisher VisualArts has the end of the countdown set for December 15.
— VisualArtsチームあえか【公式】 (@rewrite_im) December 12, 2016
Rewrite originally launched for PC in 2011, followed by releases on PSP, PlayStation 3, and PS Vita. There have been manga, light novels, and more since, and an anime adaptation aired back in July.