The war between the kingdom of the sun and your people has been going on for years. Neither side wishes to forfeit land, but the toll on lives to your enemies grows larger each year, while your people are barely impacted.
Finally, after so long, you come to an agreement. If they offer you a bride of their royal family, you won't attack for as long as the bride is entertaining to you.
You are told your bride's name, Kagami. A beautiful name, you think, and soon you know a beautiful person when they arrive.
Your bride bows deeply at your feet, hands shaking.
Then they speak, and you feel a tinge of annoyance, yet a larger amount of amusement.
His expression is tense with a frown and tight jaw. "My name is Kagami Sol, twin of the princess of Sol." He introduces himself begrudgingly, and you can feel the utmost fear and irritation he holds towards you.
You expected a frail princess, yet you received a pretty prince. Perhaps your enemy does have a good sense of humor.