ACT I

During a port call in Nagasaki, Lieutenant Benjamin Franklin Pinkerton of the U.S. Navy negotiates with marriage broker Goro with the aim of hiring a traditional house and marrying a young Japanese woman, Cio-Cio-San, or Butterfly, with whom he is smitten. The lease and marriage contract are signed for a duration of 999 years, but can be terminated at a month’s notice, allowing him to marry an American when he goes back home. Surrounded by her friends and family, Butterfly comes before her future husband and the American Consul, Sharpless. She is only fifteen and her father was forced to commit hara-kiri to save his destitute family’s honour. The ceremony is disrupted by her uncle, the Bonze. He tells everyone that the girl has forsaken her ancestral religion and converted to Christianity. Butterfly is disowned by her family, but consoled by Pinkerton. Now alone and intoxicated with desire, the young couple discover each other. Butterfly gives herself to Pinkerton ‘for life’.

ACT II

Pinkerton has left Japan, promising Butterfly that he will return in the spring, but three years have already gone by. The young woman continues to hope despite the doubts expressed by her servant, Suzuki, a life of poverty and the manoeuvrings of Goro, who is pushing her into marrying rich Yamadori. Sharpless comes to see Butterfly to break the news that Pinkerton, who will soon be returning to Japan, has settled down into a new life. However, when he finds out about the son born of their marriage, he shies away from telling her the truth. When Butterfly sees Pinkerton’s boat sailing into harbour in Nagasaki Bay, she puts on her wedding dress and decorates her house for her husband’s return.

ACT III

Having waited in vain all night, Butterfly falls asleep at dawn. Sharpless has told Pinkerton that he has a son. Accompanied by his new wife, Kate, he asks Suzuki to hand over the child so he can be brought up in the United States. When Butterfly sees Kate, she realises she has been deceived. She resigns herself to losing her son and kills herself with her father’s blade engraved with the following words: ‘May he who cannot live with honour, die with honour.’