The Cat Who Saved Books

The Cat Who Saved Books is a 2017 work of magical realism by Japanese author and physician Sosuke Natsukawa. The novel follows Rintaro Natsuki, a reclusive high school student who becomes a hikikomori and retreats from the world after the death of his beloved grandfather. Rintaro’s quiet life managing his grandfather’s secondhand bookshop is upended by the arrival of Tiger, a talking cat who needs his help to rescue books from people who mistreat them. Their fantastical adventures are a journey through grief and reconnection, exploring several themes: The Power of Books to Cultivate Empathy, The Courage to Emerge From Isolation, and The Corruption of Reading in the Modern World.

Natsukawa’s debut novel, Kamisama no karute (God’s Medical Records), was a bestseller in Japan that won the Shogakukan Fiction Prize and was adapted into a film. In 2025, the sequel to The Cat Who Saved Books was published. Titled The Cat Who Saved the Library, it focuses on a young girl who loves books but whose asthma sometimes makes reading difficult. When she discovers that books are disappearing from her library, a talking cat named Tiger helps her fight censorship.

This guide refers to the 2023 HarperCollins paperback edition.

Content Warning: The source material and guide feature depictions of death.

Plot Summary

High school student Rintaro Natsuki has become a hikikomori, reclusively withdrawing from society, because he has felt detached since the sudden death of his grandfather, his sole guardian and the owner of Natsuki Books, a secondhand bookshop. His aunt, whom he has never met, arrives to handle the funeral arrangements and informs him that he must close the shop and move in with her. Rintaro retreats into the bookshop and starts skipping school. Ryota Akiba, a popular senior and regular customer, visits him, expressing sadness over the shop’s closing and urging Rintaro to return to school. Later, the diligent class president, Sayo Yuzuki, drops off his homework, chiding him for his reclusive behavior but also showing concern. Alone in the cold shop, Rintaro feels lost and overwhelmed.

A talking ginger tabby cat named Tiger appears in the shop and asks for Rintaro’s help to rescue “imprisoned books.” Appealing to Rintaro’s love of literature, Tiger leads him through a magical corridor that extends from the back of the shop into the first labyrinth to meet the owner, the Imprisoner of Books. They arrive at a grand mansion, where they meet the Imprisoner, a famous intellectual who boasts of reading 100 books a month. He keeps his collection of more than 57,000 books locked in individual glass display cases, viewing them as trophies and considering rereading a waste of time. Rintaro challenges this philosophy, pointing out that the collection is incomplete and disorganized. He argues that the man doesn’t genuinely love books but uses them to inflate his ego, quoting his grandfather’s wisdom: “It’s the book that holds the power, not you” (40). The man’s conviction shatters, and the labyrinth collapses as the books transform into birds and fly away. Rintaro returns to Natsuki Books, where he begins cleaning the shop, following his grandfather’s old routine. Sayo visits again, and a more open Rintaro invites her for tea.

Tiger reappears to recruit Rintaro for a second mission to confront the Mutilator of Books. Sayo stops by on her way to band practice and is shocked to see and hear the talking cat. She insists on joining the mission, arguing that she can’t let Rintaro face danger alone. The trio travels to the Institute of Reading Research, a vast library filled with silent, pale-faced scholars, and descends an endless staircase to find the director, an overweight scholar who is chopping up a book with scissors while Beethoven’s Ninth Symphony plays loudly. The Mutilator explains his research, “The Streamlining of Reading” (74), which involves reducing classic stories to short synopses to make them accessible to busy people. As the director explains his methods, Sayo begins to fall under his spell, her expression turning vacant. Rintaro, recalling his grandfather’s lesson that the struggle of reading is part of its value, confronts the director. He fast-forwards the Beethoven cassette, arguing that just as rushing ruins music, summarizing a book destroys its soul. This moves the scholar, and the labyrinth dissolves as the shredded book fragments magically reassemble.

Rintaro’s moving day is only two days away, and he spends his time in the bookshop, where Sayo has become a regular visitor, inspired to read classic literature. Tiger returns for the third labyrinth, in which they will confront the Seller of Books. They journey to a skyscraper housing World’s Best Books, a major publishing company, but Tiger is denied entry. Rintaro and Sayo proceed alone to the top floor, where they meet the cynical company president. He reveals that his business model is to publish only what sells, such as cheap digests and sensationalized stories, declaring that books are merely “expendable goods.”

From the Seller’s window, Rintaro and Sayo witness a blizzard of books being thrown from surrounding buildings into a massive wasteland below. With Sayo’s encouragement, Rintaro refutes the president’s worldview, arguing that his desire for books to “survive” proves that he secretly loves them. The president’s cold facade breaks, and he allows them to leave. Back in the bookshop corridor, Tiger congratulates them. Believing that his work is done, he bids them a final farewell, revealing that his true purpose was to help Rintaro emerge from his grief.

On Rintaro’s moving day, which is also Christmas Eve, Tiger reappears with urgent news of a fourth, unforeseen labyrinth ruled by a powerful entity who has kidnapped Sayo. Motivated to save his friend, Rintaro enters the final labyrinth. During a journey in a horse-drawn carriage, Tiger reveals that he’s the soul of a book that Rintaro’s mother used to read to him. In addition, Tiger explains that cherished books can gain a soul but that neglect can warp this soul, creating a malevolent being. He leaves Rintaro at a desolate replica of Natsuki Books. There, Rintaro confronts a cold, emotionless, elderly woman, the ancient soul of a neglected book that feels forgotten by the world. She shows him visions of the three previous labyrinth masters suffering hardships as a result of Rintaro’s actions and questioning the morality of what he’s done. Feeling hopeless, Rintaro is spurred on by his determination to rescue Sayo. He pursues the woman into a dark corridor and declares that the true power of books is empathy, the ability to feel for others. His words resonate, and the three labyrinth masters reappear on screens to voice their support, validating Rintaro’s philosophy. They confirm that while his actions initially caused them hardship, they ultimately set them on more fulfilling paths. This revelation breaks the woman’s coldness, and she releases Sayo as the labyrinth dissolves.

Three months later, Rintaro has decided to stay and run Natsuki Books, having agreed with his aunt that he’ll attend school, call her regularly, and ask for help when needed. His life has found a new rhythm, and his friendship with Sayo has deepened through their shared love of books. One morning, Sayo asks Rintaro out on a date. As she leaves for school, Rintaro offers her a heartfelt thanks for her support. He then hears Tiger’s voice one last time, wishing him good luck. Accepting his new path, Rintaro settles in with a cup of tea and a book as the bell on the shop door gives a cheerful ring.