Butterflies also Love（1979）

Monica, a naive schoolgirl from a suburb of Rio de Janeiro, meets Virginia, a former neighbor, now living in Copacabana. Influenced by her, she decides to take on a double life: in the morning she is the suburban girl, in the afternoon she attends a brothel in the South Zone. One day she meets Flávio, a friend and eventual lover of Virginia. Flávio falls in love with the purity of Monica and wants to drive away her friends, for considering Virginia a bad company for her beloved.