「お前が代わりに死ね」と言われた私。妹の身代わりに冷酷な辺境伯のもとへ嫁ぎ、幸せを手に入れる

彼女には宝石姫と呼ばれる美しい妹と、妹を溺愛する両親がいる。She has a beautiful younger sister who is known as the Jewel Princess, and her parents who dote on her younger sister. Cheryl, the daughter of an earl, was born into such a family, and she believed that if she worked hard, she would be loved someday, and she has lived until today. However, what she was told was a sentence from her father: ``You must die in her sister's place.'' By order of the king, a marriage between her sister and a ruthless margrave was decided, so Cheryl was ordered to take her place and head to the frontier territory, where she was attacked by monsters and died on the way! Cheryl was attacked by monsters as planned, but died. Just as he was preparing for this, a young man with fiery red hair was saved by his fiancée, a margrave...!?