Ah Long dik goo si is a 1989 Cantonese-language Drama film directed by Johnnie To and produced by Raymond Wong under the banner of Cinema City & Films Co. A father's ex-girlfriend resurfaces after a 10-year absence wanting to take her son away from him. With his world shattered, he must decide between what is best for his son and his own future happiness. Ah long dik goo si stars Chow Yun-fat, Sylvia Chang, Yun-fat Chow, Kun-hsuan Huang, Man-tat Ng, Tian-lin Wang and Tze Tze. The screenplay is written by Philip Cheng and Ng Man-fai. The music was composed by Lo Ta-yu. Cinematography was done by Wong Wing-hang and editing by Wong Wing-ming. The motion picture has a running time of 95 minutes. It was released on 1st January 1989. The film made a box office gross of $30 million. Distribution rights for the film were acquired by Cinema City & Films Co. A father's ex-girlfriend resurfaces after a 10-year absence wanting to take her son away from him. With his world shattered, he must decide between what is best for his son and his own future happiness.