He Was Cool (2004)

Having replied to a wicked post on her school website, Ye Won keeps getting a threatening call from a boy named Ji Eun Sung. Having heard about him from her friend, she keeps running away from him. But they kissed accidentally when Ye Won was trying to escape from him. Having his lips stolen by Ye Won, Eun Sung threatens her to marry him, adding that no other girl has ever kissed him before. The only thing Ye Won can do is to obey whatever Eun Sung said. At first, Ye Won just hates him the most for his self-righteousness and unreasonableness. But she gradually finds herself starting to fall for him.