A Samurai, the father of Butterfly, has been disgraced. In the last moments before he commits Hari Kari he sells his daughter to the marriage broker, Goro. Butterfly enters the world of Geisha with her only possession, her father's sword, and dresses in her new kimono.
American naval officer, Pinkerton, and some friends are being entertained in a Geisha house. He is bewitched by one particularly beautiful geisha and Goro the marriage broker points out that the young girl in question, Butterfly, can be purchased as a ‘bride’. Butterfly is little more than a child and believes this to be a serious marriage. She betrays her religion and adopts her husband's Christian faith, committing herself to him forever.
Goro is showing Pinkerton his hilltop lover's nest when his friends arrive. The young men are absorbed in their friendship and the excitement of the mock wedding to come. Sharpless the American Consulate arrives to officiate and they all toast the American flag. Butterfly arrives and she and Pinkerton are married, but the festivities are interrupted when the Bonze, a Japanese holy man, arrives to denounce Butterfly for converting to Christianity. He declares her an outcast and the guests all depart. Butterfly prepares for her wedding night, and though she has been disgraced and feels shy she soon finds freedom in the arms of her lover. She is an American now. Dawn finds Pinkerton departing for his ship and the start of Butterfly's patient vigilance.
Three years have passed and Butterfly has borne Pinkerton a son. Butterfly and Suzuki, her maid, have become firm friends, Suzuki enduring Butterfly's blind faith that Pinkerton will return. As if in answer to Butterfly's longing, Sharpless appears with a letter from Pinkerton. The news is not good. Pinkerton has no plans to return. Butterfly's worst fears have been confirmed but she shows Sharpless Pinkerton's son and he assures her that he will notify Pinkerton.
Time passes and Butterfly is haunted by nightmares of Pinkerton with other women. As Spring breaks through winter Goro appears with a new suitor for Butterfly, the Prince Yamedori. Butterfly plays the part of the Geisha perfectly, behaving like the silly girl they assume she is. However, when the men think they have won her over she chases them from her house and is stopped only by the cannon on the harbour announcing the arrival of a ship.
It is Pinkerton's ship and Butterfly and Suzuki begin the preparations for his arrival. Dressed in her wedding kimono Butterfly waits for her husband all night, but when dawn comes there is still no sign of him.
Pinkerton shares an intimate moment with his American wife, Kate, before meeting the consulate. Sharpless is not happy to see Pinkerton and reminds him of the difficult situation ahead of him. The Americans arrive at the hilltop but, as memories of the enchanting night he spent with the fragile Butterfly and the thought of seeing her again overwhelm him, Pinkerton flees from the scene, leaving Kate to deal with Butterfly.
Butterfly hears the noise outside and runs from the house in search of Pinkerton. Instead of finding her husband she finds instead his wife and her own bitter destiny. Though filled with grief and desperation Butterfly accepts Kate as Pinkerton's wife and surrenders into her care her last reason for living, her child.
Left alone, deserted by family, husband, religion and child, Butterfly retreats back to the only thing she has left – her culture. In this culture, freedom from life's dishonour can be found through ritual suicide. Her father's Samurai sword, her only inheritance, frees Butterfly at last.