In the Ai no Kuni Mogan Airu series:

V.1 - Princess Lesson (The King's Convenient Bride)

At the age of sixteen, Hannah Renault was chosen to marry Phillip, the prince of England's Morgan Isle. After eight years of preparation, her wedding has finally arrived, and she's excited to be married to the man she fell in love with at first sight so many years ago. Hannah is a genuine and loving person, and she has long dreamed of her love-filled marriage to Phillip. When Phillip admits that he has never loved anyone and likely never will...how will she respond? And who is that dark-haired woman with such hostility in her eyes?

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V.2 - Wana ni Kakatta Princess (An Affair with the Princess)

Princess Sophie's life is turned upside down when her brother invites his old friend to Morgan Isle. Feelings Sophie had buried away so long ago begin to resurface. The last time she saw this man was ten years ago—when she ended their secret relationship. Alex's return sends Sophie into a whirlwind of passion, but when his ulterior motives are revealed, Sophie's shattered heart turns to dust.