Butterfly is a 15-year-old former geisha from the Omara district of Nagasaki. Her family lost its considerable wealth, forcing the women into the entertainment profession before she secures a marriage contract with a visiting American naval officer. She demonstrates absolute commitment to her new life by throwing away her Ottoke, statues of her ancestors, to embrace her husband's religion. Her delicate physical presence is frequently compared to fragrant flowers and fragile paper screens, masking a powerful internal willpower.

B. F. Pinkerton is a lieutenant in the United States Navy who serves aboard the gunboat Abraham Lincoln. He approaches his foreign deployment with an imperialistic perspective, viewing international women as exotic pearls to be collected during his travels. He rents a Nagasaki house with sliding paper walls on a 999-year lease that he can cancel at any month, a contract he explicitly compares to his temporary marriage. He readily toasts with whiskey to his eventual return to America, ignoring the severe social consequences his casual arrangements inflict on others.

Sharpless serves as the serious and observant United States Consul in Nagasaki. Upon hiking to Pinkerton's newly leased house, he immediately recognizes the vulnerability of the young bride and attempts to caution his countryman against breaking her delicate wings. While he possesses a deep capacity for pity and frequently acts as an emotional guide for the unfolding events, his primary allegiance remains with his fellow Americans. He struggles to directly communicate harsh realities, preferring to rely on diplomatic tact.

Suzuki is Butterfly's highly perceptive and intensely loyal servant. She manages the physical upkeep of the Nagasaki house while providing constant emotional anchoring for her young mistress. In stark contrast to Butterfly's eager assimilation, Suzuki continues to pray to Izanami and other Japanese gods, harboring pragmatic doubts about the reliability of foreign sailors. She is physically expressive in her care, readily arranging flowers and sharing in the household's anxieties.

Goro is an opportunistic and obsequious marriage broker operating in Nagasaki. For a fee of one hundred yen, he coordinates the housing lease, the servants, and the marriage contract between the naval officer and the young geisha. He operates strictly on commercial principles, directing the Registrar and the Commissioner during the official ceremonies. When his initial arrangements face social friction, he immediately attempts to broker new, more profitable marriages for his clients, frequently resorting to local gossip.

Prince Yamadori is a wealthy Japanese divorcee who actively seeks a new marriage arrangement. He possesses a regal palace in Omara, along with numerous servants and accumulated treasures. He relies on traditional matchmaking channels to court his desired bride, arriving formally with flowers to present his case. Despite facing persistent rejections, he remains confident in his financial appeal and the legal logic of his proposals.

Kate is an American woman who arrives in Nagasaki representing the conventional Western society that the naval officers idealize. She waits in the garden of the estate while the men conduct their business inside the house. She operates with a practical sense of duty, offering solutions to complex household arrangements based on American standards of family structure.

The Bonze is Butterfly's uncle and a commanding religious figure within the community. He represents the strict spiritual traditions and ancestral honor of their Japanese lineage. He dramatically interrupts the wedding reception to announce his niece's religious conversion, utilizing his loud, authoritative voice to curse her. His rigid adherence to faith successfully turns the entire extended family against the young bride in a matter of moments.

Sorrow is a young boy living within the Nagasaki household who possesses striking blue eyes and golden ringlets. His physical features heavily reflect his American heritage, setting him apart from the local community. He serves as the absolute center of his mother's world and the primary motivation behind her most significant choices. His name reflects the household's current emotional state, carrying a promise that it will change to 'Joy' when circumstances improve.

Yakuside is another of Butterfly's uncles who attends the initial wedding festivities. He demonstrates a strong preference for alcohol, immediately seeking out wine during the reception. He represents the extended family members who initially support the union for its material benefits before religious conflict shatters the gathering.