My Scary Girl (2006) Korean Movie

29-year-old Hwang Dae Woo is a successful university lecturer of English, who due to his awkward and shy nature around women, has yet to engage in any romantic relationship. When art major student Lee Mi Na suddenly moves into his apartment complex, Dae Woo asks her out and finds himself in an almost-too-good-to-be-true relationship. Yet, Mi Na seems to be hiding something sinister, and Dae Woo encounters a rather interesting twist to his fairy-tale-like first love.

Native Title: 달콤, 살벌한 연인
Also Known As: Minha Garota Assustadora , My Sweet, Yet Brutal Sweetheart