Natsuki Books was a bookshop on the edge of town. Inside, towering shelves reached the ceiling, every one crammed full of books. Rintaro Natsuki loved this space that his grandfather created. He spent many hours there, reading whatever he liked. It was the perfect refuge for a boy who tended to be a recluse. After the death of his grandfather, Rintaro is devastated and alone. It seems he will have to close the shop. Then, a talking tabby cat appears and asks Rintaro for help. The cat needs a book lover to join him on a mission. This odd couple will go on three magical adventures to save books from people who have imprisoned, mistreated, and betrayed them.