Ma Gang-se (Kang Pil-seon) is branded at work as the pervert professor and in the end, he gets fired. He thinks there's no more reasons to live and leaves on a trip by himself before he commits suicide. On his trip, he meets a mysterious woman named Sara. He spends every night with her and satisfies his erotic fantasies, However, Kang-se starts to suspect her existence as she appears and disappears all the time. Finally, the shocking truth about her is unveiled....