Winter Sonata Anime [Korean]

From Wikipedia:
"The story begins when Joon-sang, who is the son of an eminent musician, moves to Chuncheon, 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 and serious conflicts with his mother, Joon-sang believes that no one truly loves him.

On one fortuitous day on the ride to school, Joon-sang's classmate Yu-jin interrupts him on the bus. Joon-sang soon falls in love with Yu-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 memories of growing up 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 Li Min-hyung. As such, both his friends and teachers are told that Joon-sang is dead.

Ten years later, Joon-sang 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 Yu-jin sees him on the street, prompting her to put off her engagement to childhood friend Sang-hyuk. Little does she know that Joon-sang is dating her friend and sometime rival Chelin. The story's plot intensifies when Yu-jin begins work at the firm where Joon-sang is employed, and tries to find out if he is her lost lover Joon-sang."