The book, as well as the Exit Tunes partnership, are apparently created to a stage of the project being referred to as Under the Dog Episode 0.
Exit Tunes previously helped the Under the Dog team with the production of rewards during the Kickstarter campaign.
Set to come out in February, The Official Guide to UNDER THE DOG includes character designs, charts of the relationships between organizations, stills, and director Masahiro Ando’s full storyboards.