Thirteen is a 1974 Hong Kong coming-of-age film directed by Sung Tsun-shou and produced by Shaw Brothers Studio. It was based on the novel Zaoshu ("matured early") by Taiwanese novelist Kuo Liang-hui.
^ Daw-Ming Lee Historical Dictionary of Taiwan Cinema 0810879220 2012 p.400 "Two of her novels were made into films by veteran director Sung Tsun-Shou: Thirteen/Zao shou (1974) and Ask My Love from God/Ci qing ke wen tian (1978)."
Synopsis
Shih Hsin-chiao, a journalist who trained under mentor Lu Tao-jan, is a family friend of the Lus and well-liked by the children. Lu's 13-year-old daughter Chih-pai is infatuated with "Uncle Shih", but Shih sees her only as a child. Lu Tao-jan is transferred to Macau, where he has an affair with Shih's cousin. When Shih returns after a trip to Japan, he finds Chih-pai an attractive young woman. After repeatedly being rejected by Shih, Chih-pai has a relationship with a rich playboy Hung Sen, which leaves her pregnant. Desperate, she goes to the only man who can help her: Shih.