Please recommend a novel. The female protagonist transmigrated to the Prime Minister's residence and became the neglected Fourth Miss. The male protagonist is the prince of the enemy country.

Once, the female protagonist was playing Mountain Stream in her own courtyard and was heard by the injured male protagonist. The female protagonist saved the male protagonist. The female protagonist fled the house before the Prime Minister's residence was seized. The male protagonist sent someone to rescue her, but his subordinate mistakenly brought Third Miss back. The male protagonist heard Third Miss playing Mountain Stream and knew that she was not the female protagonist ~ That's all I remember ~ The female protagonist was an unfavored concubine's daughter. The male protagonist was the king of an enemy country. He seemed to be called the God of War or something. In the novel, the male protagonist seemed to have given the female protagonist a scorched tail zither. It wasn't just "A Lonely Beauty Who Doesn't Appreciate Myself" that I remembered these things ~