Sai (사이)

A brilliant heiress from the empire’s richest house has it all: wealth, brains, power, and looks. After six marriages and divorces, she is still the continent’s most sought-after bride. For the seventh, she chooses a young marquis and war hero from an old, cash-strapped family and sets three terms: protect her from assassins, respect her as a wife, and keep a separate household. With conspiracies swirling around her fortune, this might finally be the marriage that lets her live a safe, ordinary life.

At night, Princess Millaria, who dreams of an unnamed queen, becomes intertwined with the body of a queen from a hundred years ago, as if by fate. And thus, she discovers the queen's diary. "I entrust the kingdom to you. I humbly plead with you, bowing my head like this." A dark cloud loomed before her, causing confusion! "Who are you?" Ferdinand, the Duke, somehow recognizes her true identity. But crisis soon becomes an opportunity! "Cooperate with me. If you do, I will turn a blind eye to your identity." "Alright. But there's one condition." "What is it?" "It's not enough for you to just turn a blind eye to my identity. I want to be treated as a flawless queen." Millaria, who has chosen to live under the name of the queen, and Ferdinand, the Duke who knows her secret, play a duet solely for the well-being of Queen Gloria, who only desired the kingdom's peace—a requiem for the queen.