十三支族の中でも最弱と謳われる鼠族の姫・瑞英(ルェイイン)。竜王の花嫁探しのために、竜族領へと召し上げられた彼女には別の目的――獣族最大の貯蔵量を誇る書庫に忍び込み、知識を得ること――があった。竜宮入りしてから七日が経ったある日、書庫で一人読書を満喫していた瑞英は見目麗しい竜族の男に出会う。「ようやく見つけたぞ」その言葉と共に口づけをされたことから、瑞英の未来は大きく変わっていくことになり――?
Princess Ruiying of the Rat Clan, the weakest of the thirteen animal clans, was summoned to the palace of the Dragon Clan, as the Dragon King sought a bride. But instead of competing with the other princesses, her goal is to check out the dragon palace’s library, the largest in the world. Seven days after arriving, Ruying was reading alone in the library when she was caught by a handsome man of the Dragon Clan. He suddenly kisses her and says, “I’ve finally found you,” and her future is about to change forever.