The story is a separate continuation from the anime and follows the adventures of Saito and Louise when they are tasked with checking out a library after reports of ghosts inhabiting it arise. During the search Louise goes missing, and when they find her Saito and crew discover Louise has lost her memory. The librarian tells them they will need to go into the various books in the library to recover Louise's memory. Saito and friend's adventure into the world of the books then begins. Notable changes from the other entries in the series include the "tsundere meter" being reworked from a notched bar to a gradient circle gauge, while also lacking the turn based combat sections from the first entry.