Han Ping, steward to Prince Kang of Song, married a beautiful daughter of the He family. But the prince took her from him. When he protested, he was imprisoned and sentenced to hard labor on the city wall. Then his wife secretly wrote to him to say:

Rain, ceaseless rain,

Great the river, deep the water,

Yet there is sunrise in my heart.

 This letter fell into the hands of the prince, who showed it to his followers, but no one could make out its meaning. Then the minister Su He said:

 "The first line means that she is longing for him all the time, the second that they have no way of getting in touch, the third that she intends to take her life."

Then Han Ping killed himself.

His wife secretly tore her clothes. When the prince went up the tower with her, she threw herself from the top; and when his followers tried to seize her, her clothes tore away and she was dashed to death. On her belt she had left this message:

"Your Highness wishes me to live, but your servant chose to die. Please bury me with Han Ping."

The prince was angry and refused her request, ordering the local people to bury her in a separate grave.

"You speak of your endless love,” said the prince. "If you can make these tombs cone together, I will not stand in your way."

Then within one day two great catalpa trees sprang up above the two graves. In ten days they grew to an enormous size, and their branches inclined towards each other, their roots intertwined together beneath the soil, and their twigs interwound above. And two love birds, one male and one female, stayed on these trees, not departing morning or night. They billed and cooed most plaintively, and uttered heart-rending cries. The people of Song lamented the lovers' death and gave this tree the name “the tree of love.” The southerners say the birds were the spirits of Han Ping and his wife. In Suiyang today there is a town named Han Ping, and people still sing of the lovers.