Sarantuya Daaganbat

Saruul, a science student, is asked by an injured classmate Namuunaa to work part-time as a substitute in an adult goods store for a month. Katya, the Russian owner, a former ballet dancer who lives an elegant life on her own, realizes that Saruul, who comes daily to deliver the proceeds, has been suppressing herself against her parents' expectations, and tries to release her secret desires and sexual curiosity. Saruul, who lives with her family with little change in her life except for the evenings when she paints her favorite pictures, is exposed to a new world through her interaction with Katya, who has a wealth of life experience, but one incident leads to a growing distrust...

It's a movie from 2002.