After a noble heiress gets separated from her parents, she is adopted by another family. Following a car accident, she loses all her memories and lives under someone else's identity for over a decade. When her adoptive father falls seriously ill, she is forced to sell her blood at the hospital, where she unexpectedly encounters her biological parents who desperately need her rare blood type for their son's transfusion. Her biological mother generously pays for her adoptive father's medical bills and demands that the heiress be on standby as a blood donor for her son. However, the son, enraged by the heiress accidentally touching a photo of him and his long-lost sister, subjects her to relentless humiliation, with his doting mother abetting the abuse, unaware that the girl they mistreat is the daughter they've been searching for all these years.