American Navy Lieutenant Pinkerton falls in love with young Cio-Cio-San, called Butterfly, while stationed in Japan. Knowing he will be marrying an American woman upon his return, he nevertheless enters into marriage with the young Japanese woman. He ignores the warnings of his friend Consul Sharpless that Butterfly takes his promise seriously. Three years later Pinkerton has returned to the USA, and Butterfly - by now the mother of a son - is eagerly awaiting his return. When Pinkerton's ship finally arrives in the port of Nagasaki, the young woman sees herself at the destination of her dreams. However, after she learns that her lover has only come to collect the child, she commits suicide.