Jina is an exceptional employee at a call center for a credit card company. She has always preferred to keep her distance from others and prefers to live and work alone. Building close relationships has never been her thing. However, one day, she receives shocking news about her irritating next-door neighbor. He had passed away several days ago, all alone in his apartment. This news deeply unsettles Jina, and she finds herself feeling vulnerable and alone. In an attempt to regain a sense of security, she decides to turn on the home camera that her mother had installed at their house a long time ago.