Mashirubesho Reijo: Densetsu no Mashirubesho Oshufuku Shitara Saikyou no Seirei ga Mikata ni Narimashita (Kuruna Ototo Denka ga Nazeka Itsumo Soba ni Imasu)

Jane, the daughter of an earl, is shunned by her father, brothers, and even the maids. Her only solace is the old family library. She spends her time by restoring badly damaged books. One day, Jane's aunt recommends her to work as a book restorer at Lufara Kingdom's Royal Restoration Wing. The king's younger brother, Prince Raymond, oversees the Restoration Wing. Jane had always thought that the cool, high-ranking, hard-to-approach prince was in a world far removed from her own, but thanks to a certain happening, the two get closer... A heart-swooning romance between the quiet and unassuming, yet hardworking heroine and the cool prince! (Source: MangaPlaza)