Tucked away in a cozy corner of Shinjuku is Frère, a share bookstore where individual shelf owners curate and sell books from their own rented spaces. This unique establishment also has two resident cat mascots, former stray Chiyo and the shy Sumi. The narrative follows an interconnected cast of patrons and shelf owners, including a hairstylist struggling to keep up with trends, a student trying to make ends meet, and a bartender eager to understand people through literature. The stories explore why people read, buy, and most importantly, share books with others.

Each character appears initially as a minor figure before becoming the focus of their own chapter, creating a natural sense of flow through the book. One shelf owner leaves handwritten reviews in every book he sells, another sells her own handbound works, and a third struggles to find the right way to appeal to readers. A prolific reader and reviewer who has built a significant audience for his book impressions serves as a connecting thread, bringing together people from a family in Okayama, a young man struggling with unemployment, and a woman whose awkwardness prevents her from trusting her own enjoyment of things. The cats serve as more than decoration, representing different types of readers through light metaphor, though this theme is not heavily developed.

The narrative centers on the concept of a shared bookstore, a real phenomenon gaining popularity in Japan where individuals rent shelves as their own micro-bookstores. One of the most poignant moments occurs when an elderly woman takes a walk through her neighborhood and, for the first time in years, truly sees her surroundings. The book asks readers to simply take a moment to notice themselves and their surroundings and just be present in those things. Through its interconnected short stories, the light novel explores how people have their lives and outlooks shifted by the books they buy, read, and sell in unpredictable ways.