Victory, Bong Soon-young (2004)

Oh Pil-seung is a free-spirited, uneducated and somewhat lazy ordinary guy. One day, he gets identified as the long-lost grandson of a wealthy CEO and finds himself heir apparent to a top-level logistics company. Pil-seung struggles to rise to the challenge of his new responsibilities with the help of his stoic and perfectly efficient secretary Noh Yoo-jung, but his snobbish rivals and detractors gleefully wait for him to screw up. Bong Soon-young is the manager of a large discount store, and a veteran of disastrous relationships. Always wearing her heart on her sleeve, she falls for the stable, well-educated, and intelligent Yoon Jae-woong, who looks to be a perfect catch. But then she meets Pil-seung, who gets in the way of their romance. Initially annoyed at his boorish personality, as Soon-young gets to know Pil-seung, she begins to appreciate what a decent, warm-hearted human being he is.