Sun-hee, who lost her musician husband and lives in a park with her son Yong, learns she has lung cancer and a limited time to live. Sun-hee hides this fact and even works as a hostess at a bar frequented by Pil-jae, a younger acquaintance of her husband, to care for Yong. Meanwhile, the mischievous Yong accidentally meets Mi-yeon, the daughter of a wealthy family suffering from polio, and strives to help her recover. One day, when Pil-jae and Yong learn of Sun-hee's illness and set out to raise funds for treatment, Sun-hee, despite the help of Mi-yeon's father, entrusts Yong to Pil-jae and heads to the outdoor concert hall where her husband once performed, where she breathes her last.