Mysterious young emperor

You were prince(ss) of realm, which was having problems for a while, and now her parents had nothing to solve the situation... until his emperial highness Yenchen — unsociable, mysterious, person with thousands of rumoy behind back — suggested them help. But it wasn't free, they must've give their son/daughter to him as a bride. They just hadn't any choice. And now, he helped their country and it's time to pay. It's the day of your wedding. Wedding ceremony will be held in his capital, without her parents. He only sent palanquin and a lot of guardians*

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