As expected, not much info was revealed yet (they're still preparing the main visual of the new beautiful fighters), but it does mention that the visual books will have beautiful fighters fighting each other with "grimoires", a.k.a. books of magic, and that the new world will "resemble a picture book, i.e. a book of magic" (that could mean a fairy-like setting), with the world having a dark atmosphere.
In some way, I guess like the "rebellion" separated the characters in the 2nd series, the "grimoires" will impregnate the atmosphere and the lives of the new chars.
