Dansou Oujo no Akusai Keikaku: Danna-sama ga Zenzen Rikon ni Oujitekuremasen

Eddie has lived her whole life disguised as a prince, hiding the truth that she is a woman. When her loyal aide Harold discovers her secret, she is shocked not by punishment but by an unexpected royal command: she must become his wife. Determined to make him regret the marriage, Eddie sets out to be the worst bride imaginable. Yet her efforts only draw more affection from Harold, whose devotion never wavers. What began as a forced union soon blossoms into something far more tender, leaving Eddie to wonder if this unwanted marriage might be the love she has always longed for.

Source: MU