Twenty years before, during the Japanese occupation of Taiwan, Baol Chai, a young pregnant woman goes to Tokyo to determine whether her then-husband is having an affair. Upon learning the truth, she leaves him without notice. Shortly after, her baby daughter, Xi Lian, is born. Bao Chai leaves Japan after the second World War, and returns to Taiwan with Xi Lian.
Xi Lian is now 20 and starting her life as a schoolteacher. She finds love in Chu Cheng, the school's new teacher from mainland China. A taboo during the political unrest of the period, the relationship between the mainlander and the Taiwanese girl is fueled by the stealthy exchange of glances and secret rendez-vous of the two young lovers.
As Bao Chai tries to intervene, things become more complicated. She starts to intercept letters from Chu Cheng to Xi Lian and reads them herself. Bao Chai finds herself becoming more involved in her daughter's affair than she ever intended. Meanwhile, something is awakened in her that has been buried for most of her adult life－Lust.
The vulnerabilities of all the characters come to a boil. Inevitably, what happens between them changes their lives forever...