Devil Beside You (2005)

Devil Beside You, originally a Japanese manga turned Taiwanese drama, basically revolves around a typical love triangle. When Qi Yue's attempt to tell her crush, Yuan Yi, how she really feels falters, her world turns upside down as she becomes tormented by the school's Prince, Ah Meng, who ends up with the letter of her confession. Known for his devilish ways, Ah Meng always gets his way and he only desires Qi Yue. Qi Yue breaks through his hard exterior and falls in love with the devil. Unfortunately, fate doesn't agree on their union when they find out that they are soon to be step-siblings.