Bookish high school student Rintaro Natsuki is about to close the secondhand bookstore he inherited from his beloved bookworm grandfather. Then, a talking cat appears with an unusual request. The feline asks for --- or rather, demands --- the teenager’s help in saving books with him. The world is full of lonely books left unread and unloved, and the cat and Rintaro must liberate them from their neglectful owners. Their mission sends this odd couple on an amazing journey, where they enter different mazes to set books free. It all culminates in one final, unforgettable challenge --- the last maze that awaits leads Rintaro down a realm only the bravest dare enter.