Winter Sonata (2002) (K-Drama)

Joon-sang moves to a new high school in search for his biological father. Yu-jin and Sang-hyuk are close childhood friends, although Sang-hyuk wants to be more than a friend, Yu-jin sees him as a brother. On a trip together with other high school mates, Oh Chelin, Jin-suk and Yong-kuk, Yu-jin is saved after an accident by Joon-sang. They become close and she opens up his cold heart. However, circumstances and fate dictate that their love will never be. He abruptly disappears from their lives.

Ten years later, the old High School buddies gather to celebrate Yu-jin and Sang-hyuk's soon-to-be wedding. Yu-jin, who was deeply in love with Joon-sang, still has a fire in her heart for him. But at the party, Oh Chelin's new boyfriend arrives, who appears the same as Joon-sang.