France, 1861. When an epidemic threatens to wipe out the silk trade in France, Herve Joncour (a young silkworm breeder) has to travel overland to distant Japan, out of bounds to foreigners, to smuggle out healthy silkworms. In the course of his secret negotiations with the local baron, Joncour's attention is arrested by the man's concubine, a girl who does not have oriental eyes. Although they are unable to exchange so much as a word, love blossoms between them, a love that is conveyed in a number of recondite messages. How their secret affair develops is told in this remarkable love story.