Lee Soo Hyun belongs to a special international narcotic drug crime investigation unit. He witnessed the murder of his mother at the hands of a gangster as a child. Suh Ji Woo is the first love from Soo Hyun's childhood with whom he was seperated from. Soo Hyun is adopted into Kang Min Ki's family and both grew up to become NIS agents. Ji Woo and Soo Hyun are accidentally reunited when the beautiful Ji Woo caught the attention of playboy Kang Min Ki. She and Soo Hyun are seperated once again because of Soo Hyun's vengence against his parent's enemies.