Double Suicide (movie, 1969)

Successful and married with children, paper-mill owner Jihei knows better than to contradict the strict social and moral codes of 18th-century Japan. But when he meets the lovely courtesan Koharu, he becomes a man obsessed. Koharu returns his love, even foregoing other customers while Jihei schemes to somehow buy her freedom. His efforts yield ruinous consequences for his business and his family life, and Koharu is meanwhile purchased by another client.