Iku (Nana Eikura) becomes part of the Library Defense Force after a team member rescues a significant book from being censored. She is placed under the supervision of Atsushi (Junichi Okada) and, despite his tough demeanor, she perseveres and seeks out the person who saved her book. Meanwhile, she starts to develop feelings for Atsushi. At the library, Iku encounters Marie (Tao Tsuchiya), a high school student with a hearing impairment who is also childhood friends with Mikihisa (Kei Tanaka). Iku notices Marie’s deep affection for Mikihisa. Asako (Chiaki Kuriyama) is a clerk for the Library Task Force and often meets with curator Shuji (Aoi Nakamura), which stirs complex emotions in Hikaru (Sota Fukushi). The situation escalates when Mikihisa is detained for recommending a book to Marie, with the official reason being that the book is deemed inappropriate for individuals with disabilities. This arrest infuriates the members of the Library Task Force.