Gawahi no Oshigoto wa Shuryo desu.

Annuella, the daughter of a Marquess, is abruptly told by her fiancé, Crown Prince Thaddeus, that their engagement is off.

Declaring his intention to make Millia, a Duke's daughter, his lawful wife, Thaddeus commands Annuella to step down as his official consort. Instead, he orders her to accept the position of "Secondary Consort"—a role that is, for all intents and purposes, nothing more than a glorified mistress.

Helpless to resist, Annuella initially accepts this humiliation. However, having been stripped of both her honor and dignity, she eventually realizes that she owes no loyalty to this sham of a marriage.

"If I'm just a side piece, I have no obligation to behave!" She resolves to stop caring what they think and decides to live her life exactly as she pleases...