Once upon a rainbow (1982)

Fong and Angie were close friends when they were in school but departed after graduation. Fong continued her further education in a training center. Angie worked in a studio and had a crush on a guy classmate Cheung, who was also attracted to Angie. Though Angie had feeling on Cheung, but she found out about Fong's infatuation so refused to date Cheung. One night, Angie was particularly low in spirits, she went to see Cheung at the club where he sang. She ended up sleeping with him. Stricken by a guilty conscience, Angie refused to see Cheung again. Fong found that Cheung didn't like him so she dedicated herself into course. At the graduation performance, Fong invited Angie to go but Angle didn't show up. Fong kept calling Angie and eventually she got through and found out that Angie had drown in the swimming pool.