During the final years of the Chen Dynasty, as its downfall became imminent, Xu Deyan, the imperial son-in-law, and his wife, Princess Lechang, feared they would not be able to stay together. They broke a bronze mirror into two halves, each taking one piece, and made a solemn pact to reunite on the fifteenth day of the first lunar month, by selling their respective mirror halves in the market square of the capital.

After the Chen Dynasty fell, Princess Lechang was taken into the household of Yang Su, a high-ranking official of the Sui Dynasty.

True to his word, Xu Deyan endured many hardships, eventually making his way to the capital on the appointed day. There, he found an old man selling half a broken mirror, recognizing it as his wife's piece. Through this, he managed to locate Princess Lechang, and the couple was eventually reunited, proving their enduring love.