A young girl works at a call-in centre for a credit card company. Aside from greeting customers and looking at her cellphone constantly, she hasn't much of a social life. She is a misanthrope, avoiding any human interaction. When she is forced to have a trainee she is rude and abrupt to her.
All this is well done by the main actress (Jeong Da-eun) and she certainly can't be accused of over-acting. The film is also sprinkled with humour, which alleviates the atmosphere and prevents the film from being overly world-weary.
Obviously the purpose is to demonstrate the alienation and loneliness of young people in today's' world - yet hasn't this been a perennial problem - listen to some of the folk music from the 1960s.