The library contains thousands of books and periodicals, with each of its floors lined wall-to-wall with bookshelves. There are several floors connected by a spiral staircase, and higher books can be reached by ladders. The library also has chairs and tables to accommodate witches' studies. It houses a vast repository of magical knowledge as well as yearbooks for each graduating class.
While Luna Nova's Library covers a broad corpus of information about magic, for knowledge of ancient arcana, one must go to the Luna Nova Archives, which can only be entered with a secret key.
Akko goes to the library to look for information to improve the parade to organize. She reads lots of books, including one about ships, though she fails with most of what she gets.
Ursula goes to the library to confirm her hunch that the Jennifer Memorial Tree's decline is temporary and caused by the gestation of Pappiliodya chrysalises on its roots. As she re-reads a book on the subject she realizes she was right and that a "miracle was approaching". At the Jennifer Memorial Garden, Akko has the same realization and casts the Pappiliodya Spell. Back at the library, as Ursula reads the same description of the Papilliodya found in the Chariot cards, students marvel at the magic butterflies flying outside the window, just as Ursula explains "the delight of their first flight brings hope to the hearts of those who behold them".
Ursula takes Akko to the Library to talk about the jobs pursued by alumnae, and what her career path could be. Akko reaffirms her commitment to using magic to make people happy, like Chariot. The graduation books are seen again in "Chariot of Fire". Ursula is somewhat taken aback when Akko asks her if her childhood dream was to become a teacher.
Shortly before the events of the episode, Diana looks in the Library for information about the Nine Olde Witches but comes up empty-handed. Diana goes to the headmistress' office to ask for help and the headmistress Holbrooke gives her a key to the Luna Nova Reference Archives, where records about ancient magic are stored.
Ursula meets Diana in the Library, who is investigating the background of the new teacher, Croix. Ursula inadvertently reveals intimate knowledge of Croix but then denies being close to her, making Diana suspicious. Diana then looks up Ursula herself in the yearbooks.
Akko and Amanda meet Ursula in the library, who was collecting books for Professor Finnelan.
Akko goes to the library in an effort to find the meaning of the Sixth Word of Seven Words of Arcturus, Lyonne. Since Ursula told her that the Word is particularly precious, she looks through inspirational quotes to find it. She is approached by Hannah and Barbara who thank her for bringing Diana back to school. Akko ponders the enigma of the Word; she won't be able to find it if she looks for it. Croix approaches her and tells her that Chariot found the Sixth Word after climbing Wagandea.