Dr. Sadao Hoki is a highly skilled Japanese surgeon who lives on the coast with his family. He spent significant time studying medicine in the United States, where he met his wife, before returning to Japan. His medical expertise is vital to the war effort, particularly his ongoing research into disinfecting battle wounds and his position treating an important, ailing general. Sadao experiences a severe internal crisis when an injured American washes up on his property, tearing him between his ingrained patriotic duty to report the soldier and his Hippocratic oath to save lives.

Hana is a devoted wife and mother who met her husband, Sadao, while they were both studying in America. Sadao only allowed himself to fall in love with her after confirming she was ethnically Japanese, ensuring his father's approval. In her household, Hana maintains the outward obedience expected of a traditional wife but actively voices her concerns behind closed doors. The sudden arrival of a wounded American soldier deeply frightens her, placing her natural maternal compassion at odds with her acute fear of discovery by the military police.

Tom is a young, blond American Naval soldier who recently escaped from a prisoner-of-war camp. He is discovered starving, dirty, and suffering from a severe gunshot wound. Barely twenty-five years old, his physical condition and rough scars indicate brutal treatment during his captivity, leaving him entirely dependent on the unexpected mercy of an enemy doctor.

Yumi is a fiercely patriotic domestic servant and devoted caregiver to the Hoki children. She strictly adheres to imperial propaganda, viewing all Americans as violent enemies of Japan. Her stubborn refusal to clean the wounded soldier creates immediate friction in the house, demonstrating her rigid adherence to national expectations over her employer's direct commands. Despite her defiance regarding the prisoner, she remains deeply attached to the children in her care, particularly the baby.