8-year-old Billie leans on her vivid imagination, and her loyal best friend Sherry, to unravel the web of secrets shrouding her mother's true identity.
Jung-seo, an artist who draws vampire webtoons, heads to her father, Young-joo, who runs a restaurant in Mukho Port in Gangwon-do. She brings a saxophone that her mother, Mi-young, had kept as an IOU symbol. There, Jung-seo gets tangled up in her family members' unfamiliar desires. As she confronts her roots and shaky presence, Jung-seo makes a choice for herself.