The story begins when Joon-Sang, the son of an eminent musician, moves to Chooncheon, a rural city in South Korea. As an extraordinarily talented student, Joon-Sang is welcomed by his fellow students as well as teachers, but remains a quiet, introverted young man. As a result of his belief that his father is dead, as well as conflict with his mother, Joon-Sang believes that no one truly loves him.
One day on the ride to school, Joon-Sang's classmate Yoo-Jin interrupts him on the bus. Joon-Sang soon falls in love with Yoo-Jin, who opens herself to him with an innocent heart. Their love, however, is cut short after Joon-Sang is involved in a serious auto-accident and, due to brain damage, is unable to recall his past life.
Joon-Sang's mother, desiring Joon-Sang's love and respect, has Joon-Sang brainwashed by a psychologist, so that Joon-Sang will not remember his painful childhood, as an illegitimate child. As a result, Joon-Sang's memories prior to the accident are erased. Joon-Sang's mother decides to move to the United States with Joon-Sang, where he can start a new life under the identity of Lee Min-Hyeong. His friends and teachers are told that Joon-Sang is dead.
Ten years later, Min-Hyeong is an award-winning architect in the United States. He does not remember anything about his life in Korea. He is completely different, an open-minded person who cares about other people, including his mother. He returns to Korea and Yoo-Jin sees him on the street, prompting her to put off her engagement to childhood friend Sang-Hyeok. Little does she know that Min-Hyeong is dating her friend and sometime rival Che-Rin. The story's plot intensifies when Yoo-Jin begins work at the firm where Min-Hyeong is employed, and tries to find out if he is her lost lover Joon-Sang.