After watching the play The Quartet, Heon, Eun, Jun, and Kyeong decide to join an acting workshop. The one month-long class is led by Mirae, an actress. Heon, as the youngest employee of a theater company, is assigned only chores. Eun spends tedious hours tidying up in a secondhand bookstore. Jun spends most of his time acting in short films, and Kyeong is a photographer who aspires to be an actor. Mirae thoughtfully considers each of their motivations for acting, the deep emotions they might be hiding, and the self-image they are trying to project, believing that their acting is a mirror of their inner self. As part of a character-building session, Mirae shows them the diary of an anonymous person. She instructs each of them to read the diary, imagine the person writing it, and then do their best to act out that person. How different will each of their interpretations be?