Perdi, known widely throughout the continent, is a very famous author of adult novels. But Perdi's true identity is actually Vivian, the Imperial Night Librarian.

Vivian sends over the 4th draft of her latest novel to her publisher to be reviewed, but her work is criticized because the way she writes hetero s*x scenes isn't erot*c at all.

"What, so you're saying I'll only know what sexual relationships are like after I experience it myself? But what can I do when I'm bound to a chastity contract?"

Unfortunately for Vivian, she had to sign a chastity contract in order to be hired as an imperial servant, and has been forced to remain a virgin ever since. Worse still, only a member of the imperial family could break the contract… but Vivian only has eyes for Ray, a mysterious man who visits the library every night.

But as it turns out, Ray is the imperial archduke and the emperor's brother! One day, he approaches her with a sweet offer that she can't resist…