Mi-jeong, Ji-hye and Ji-hye's boyfriend, Geon-soo, live in the same house. They enjoy having sex without being disturbed by each other. While Ji-hye and Geon-soo are out, Mi-jeong finds Geon-soo's camera and finds out that he is the one who has been stalking her. Mi-jeong wants to ask him about it, but she's already fallen for him. In the end, they turn into a secret relationship. One day, Mi-jeong suggests they stalk Ji-hye...
Mi-jeong is a divorcee. On her way home after work one day, she feels she is being stalked by someone. She's scared to be home alone without even a husband, so she asks a close friend named Ji-hye to move in with her. Ji-hye, who needed a place to stay, moves in. With permission from Mi-jeong, Ji-hye brings her boyfriend, Geon-soo, into the house, and Mi-jeong starts developing feelings for him.
Min-joong and Ga-hee are a campus couple and friends with Geun-tae. Geun-tae has a crush on Ga-hee and asks her out to dinner to tell her how he feels about her. Ga-hee knows how he feels but she tells him she is in love with Min-joong and doesn't acknowledge his feelings for her. Geun-tae isn't happy with how Min-joong treats Ga-hee and feels bad for her. So Geun-tae comes up with a plan to break them apart by introducing a girl named Eun-bit to them...
