In the Flow Empire—a land where magic and divine power exist in balance—it is said that a "True Saintess" descends once every three thousand years. The two sisters born to the prestigious Marquis Euhiria family, the elder Ria Euhiria and the younger Guest, drew attention from a young age as candidates. No one doubted that Guest, gifted in both beauty and talent and showing signs of divine power, was the Saintess. —But behind the scenes, Ria secretly harbored growing jealousy toward her sister, nurturing a cold malice in a place no one could see.

However, one day, those expectations were overturned. The quiet and reserved elder sister, Ria, suddenly manifested overwhelming "divine power," transforming into a figure before whom even the Church bowed. The positions were reversed, and all praise and trust were poured onto Ria. But that miracle was a falsehood. Ria had dabbled in forbidden books, manipulating black magic to masquerade as divine power. The price—human lives. And that shadow was a direct continuation of the malice she once directed at her sister.

Eventually, the two were welcomed into the Imperial Church to begin their duties as Saintesses. But there, three powerful men appeared, each harboring different intentions. Grand Duke Urban Spirit, who bears an ancient curse within his body. Emperor Valus Weiner, who seeks to shake the world's balance by taking the Saintess into his hands. And Duke Iolete Snuff, who continues to search for the "True Saintess" who once saved his life.

A fake Saintess and a girl who was supposed to be unchosen. Amidst intertwining jealousy, lies, and an obsession for salvation, the truth quietly bares its fangs—.