Saint Beryl, tasked with identifying the demon among three families with inhuman power and influence, must rely solely on her divine abilities to uncover the truth.

"Who will you marry?"

In order to escape the hellish lives she endured in her previous two lifetimes, Beryl chooses Duke Vine, the true demon. She makes this choice not only to survive and avoid a brutal death but also in the hope of exacting cruel revenge on those who once killed her.

Thus, Beryl enters the demon’s castle. Having only learned how to suppress desire at the temple, Beryl soon discovers what it truly means to desire through the irreverent and seductive demon, Vine…!