Tamiko is a librarian who works in the annex of a university library, a job she treasures because it allows her to be alongside her senior colleague and crush, Kaitō, who manages the facility. Her quiet, routine-driven life among the bookshelves takes an unexpected turn with the arrival of Seta, a troublesome young university student who begins working in the same library annex. The narrative revolves around this unlikely trio, exploring the evolving dynamics within the library walls. While Tamiko nurtures her feelings for the calm and dependable Kaitō, she must learn to navigate the chaotic energy of Seta, who disrupts her peaceful workspace. As the three characters work side by side, the bonds between them grow more complex, with the quiet library annex serving as the backdrop for a story of romance, rivalry, and personal growth.