The Dragon King's Imperial Wrath: Falling in Love with the Bookish Princess of the Rat Clan Series by Akira Shikimi, Akiko Kawano

Thirteen clans rule the land, and the Rat Clan is the weakest. Ruiying, the princess of the Rat Clan, is summoned to the land of the dominating Dragon Clan along with princesses from the other clans. The Dragon King seeks a bride, and they are all candidates! Yet instead of vying for the Dragon King's favor, Ruiying takes refuge in the palace's enormous library--a place she can read to her heart's content... moreThirteen clans rule the land, and the Rat Clan is the weakest. Ruiying, the princess of the Rat Clan, is summoned to the land of the dominating Dragon Clan along with princesses from the other clans. The Dragon King seeks a bride, and they are all candidates! Yet instead of vying for the Dragon King's favor, Ruiying takes refuge in the palace's enormous library--a place she can read to her heart's content. It's there that the Dragon King discovers her by chance, sparking an immediate connection that will change Ruiying's life forever! less