The new Emperor of Xai Qing and The Houses of Nine, 19-year-old Ru LeiShun, is not particularly liked by the eight noble families he must now lead. To soothe tempers, he initiates the Law of Alliance, which requires each House to provide one blood heir to compete for his hand. The winner's family will become the second most powerful family in Xai Qing, and the winner themself will become the second most powerful voice in all the nation.

20-year-old Ye Enlai is the half-blood heir to The House of Vines, the weakest of all the Houses of Nine. Commanded by his father, he has no choice but to compete in the contest for the new Emperor's hand. The last thing he expects is to fall in love with him.

As Ye Enlai prepares to have his heart broken, he learns of a plot to kill the Emperor's younger brother and feels he has no choice but to warn Ru LeiShun before it's too late. But how to convince him of such treachery when the traitor is not only the Emperor's favorite candidate for marriage but the man's very own best friend?