A young US Navy lieutenant, Pinkerton, stationed in Nagasaki has taken a 999-year lease on a home. Included on the lease – which can be broken at any time – are three servants and a young geisha wife, Cio-Cio-San, known as Madam Butterfly. The American consul warns Pinkerton against taking this marriage lightly. Pinkerton declares he loves Cio-Cio-San, but nonetheless toasts the prospect of a future American wife.
Pinkerton is absent for three years, leaving Butterfly and their son, Sorrow, in the house in Nagasaki. She is convinced her husband will come back to her and envisages his return, chiding her maid , Suzuki, for doubting Pinkerton. Steadfast in her love, she rejects a princely suitor the marriage broker, Goro, brings to meet her. When Pinkerton does return, the consul reveals he has an American wife. Butterfly realises she has been abandoned but believes Pinkerton will come to her when he learns he has a son.
Pinkerton, his wife, Kate and the consul arrive at Butterfly’s house. She is sleeping so they ask Suzuki to tell her they wish to take Sorrow with them to America. Overcome by guilt, Pinkerton leaves. Butterfly enters, realises who Kate is and reluctantly agrees to give up her son, on condition Pinkerton himself returns to collect the boy.
Alone, Butterfly takes out a dagger – she will die with honour rather than live on in shame. Pinkerton returns to witness this tragic ending.