Yeon-soo has a bright and positive personality. Since her father died, she lives with her mother and younger brother. Despite their financially difficult situation, Yeon-soo lives happily with her family and her boyfriend Jung-hyun.
But then Yeon-soo's life changes drastically. Her mother is killed and Yeon-soo is accused of murdering her. Every piece of evidence points to her as her mother's killer.