「喜びなさいお姉さま！　その使い道のない純潔、ワタシのために有効活用させてあげるっ！」

Lady Margaret Wordsworth is ordered to stand in for her sister on the wedding night with Percival, the Marquess Stroud's heir and her sister's fiancé, as her sister had already lost her purity from her nightly escapades.

To make matters worse, Percival has reportedly just lost his long-time fiancée and is heartbroken, apparently harboring strong resentment towards this forced marriage itself.

Margaret, having been oppressed by her family for over ten years, has no right to refuse. So, expecting cold treatment, she impersonates her sister and goes to the Marquess Stroud's mansion—only to find an utterly unexpected, exceptionally warm reception awaiting her!?

「――俺は、本当の君が知りたい」

A romantic comedy that begins with a lie, featuring a young countess's daughter prone to giving up and a marquis's son who can see through deception.