Details
LifeWonders is releasing a colored collection of official game-related material, including various illustrations and terminology. This will include CG of Main Quest Chapters 1 through 3, Christmas 2016, Valentine's 2017, "standing pictures", artwork from promotional material, details for each character (height, weight, Summon date), and other illustrations.
Sample content can be found on the news page. B5 sized, full color, 80 pages, Japanese only.
LifeWonders is scheduling to release this late August, 2018 on BOOTH, and physically at special events.