Da Mi, a young high school student with a heart condition, leaves her adoptive parents to live with Geum La Hui, her biological mother. When Da Mi arrives at La Hui's place, she is overwhelmed by her riches. However, she soon starts to wonder if her mother's intentions are genuine after an incident with her affluent grandfather. 

Da Mi leaves La Hui and promises she won't let her receive any money from her grandfather. Meanwhile, Scarlet Letter spreads rumours of Da Mi and her stepfather's promiscuous relationship, causing widespread outrage and chaos. To make things right, Da Mi takes things into her own hands and calls everyone to the park.