Yoon Soo-wan (Ku Hye-sun) and Park Dong-joo (Lee Sang-yoon) were each other’s first loves. They were forced to separate due to some painful family circumstances. Soo-wan, who is blind, undergoes an eye transplant surgery that restores her sight.

Twelve years later, Soo-wan works as an emergency rescue worker in 119 and Dong-joo is a surgeon. He came back from United States to South Korea as Dylan Park. They meet each other again. However, Soo-wan is engaged to a neurosurgeon, Kang Ji Woon (Kim Ji-seok). Because of this, Dong-joo keeps quiet and did not reveal his identity to Soo-wan. He decides to go back to United States.

Will Soo-wan find out that Doctor Dylan Park is actually her first love, Park Dong-joo? Will they get back together despite the obstacles that they are facing?