The original play - the love story of  Liang Shanbo and Zhu Yingtai
"Butterfly Lovers" is known in China by the name "Liang Shanbo and Zhu Yingtai".  The heroine of the story is Zhu Yingtai, a 16-year-old girl of good breeding eager to learn, who consequently dresses as a boy and sets out to begin school to study for the second grade scholars ´examination.  He - Liang Shanbo - is a boy one year her senior and of humble origins.  Zhu Yingtai is accompanied by her maid, who like her mistress is in a boy´s disguise.

Act 1 (On the Straw Bridge)
The young people meet on their way to study in the city of Hangzhou, Liang Shanbo naturally takes Zhu Yingtai for a boy. However, in their first dialogue it transpires that Liang Shanbo considers women his equals who should be allowed to study too. The young become friends, take the vows of friendship and proceed together to seek for a master in Hangzhou.

Act 2 (In the Private School)
The Master accepts the young people in his class, but his wife is puzzled by the younger student´s effeminate ways. There is but one vacant room in the Master´s house, so Liang Shanbo and Zhu Yingtai have to share a room and a bed. In the evening Liang Shanbo is surprised to notice that his companion´s ears are pierced, for only women wear earrings. But he soon forgets about the whole thing.

Act 3 (In the Library)
The two friends are studying together. They are reading historical tales about important and powerful women. By and by Zhu Yingtai falls in love with Liang Shanbo, but while disguised as a boy she can naturally not disclose her feelings.  After three years of coexistence Zhu Yingtai receives a message that she must immediately return to her father´s house.

Act 4 (At the Roadside Inn)
Liang Shanbo sets out to see Zhu Yingtai off. The atmosphere is wistful, and Zhu Yingtai finds it almost impossible not to reveal her true identity and feelings. Finally she hits on a brilliant idea of telling that there is a twin sister at home, willing to marry Liang Shanbo. She herself would act as matchmaker. So they part with promises to meet again soon, so Liang Shanbo can marry the "twin sister", i.e. Zhu Yingtai herself.

Act 5 (In the Library of the Private School)
Liang Shanbo is pining for Zhu Yingtai; he has lost his appetite and is daydreaming of a visit for Zhu´s home. The Master´s wife reveals the truth about Zhu Yingtai and gives Liang Shanbo a butterfly-shaped jade pendant that Zhu Yingtai had left him as and engagement present.

Act 6 (In Zhu Yingtai´s House)
Zhu Yingtai is awaiting the arrival of Liang Shanbo, when her father comes and tells that a matchmaker has been to see him. It transpires that the father has promised his daughter to a rich and influential man, instead of the penniless Liang Shanbo. An argument develops between father and daughter, and the father accuses his daughter for obstinacy and for breaking tradition. In the middle of the argument a servant announces Liang Shanbo.

Act 7 (In the Tower Room)
Liang Shanbo and Zhu Yingtai are having a tête-à-tête in the tower room. Zhu tells Liang the terrible news: her father has promised her to another man. Liang is beside himself and demands that the marriage plans be cancelled. However, the lovers realize that there will be no future for them. Their leave-taking is most tragic.

Act 8 (On the Straw Bridge)
Liang Shanbo is moaning his fate and reminiscing about the happy times with Zhu.  Liang cannot bear the torment and falls dead on the ground.

Act 9 (On the Tower Room)
There are piles of wedding fineries before Zhu Yingtai, but she is totally uninterested. She learns of Liang Shanbo´s death and is deeply distressed. She consents to ascent the bridal palanquin only on condition that she be allowed to visit Liang´s grave on her way to the bridal house. She also insists on donning the white mourning garments over her red wedding dress.

Act 10 (At the Grave of Liang Shanbo)
Overcome by self-accusations Zhu Yingtai begs for forgiveness of Liang´s soul. A storm breaks and as a lightning strikes, Liang´s grave opens and swallows Zhu Yingtai. Her maid tries to save Zhu by clutching her clothes, but like a miracle the torn shreds turn into butterflies.  A brilliant rainbow appears in the sky, and the butterflies fly in pairs. In the background, a chorus is heard singing " the blossom time butterflies will marry, for thousand of years, inseparable generation after generation, Liang Shanbo and Zhu Yingtai."