"I can"t stop thinking about you!""I can"t stop thinking about you too..."

　　Sang-woo"s daily life changes 180 degrees ever since his sister"s friend Jeong-hee comes to live in their house. Everytime he sees her walking around the house with wet hair and wearing just a big T-shirt, he gets erotic thoughts. He dreams of having sex with her just once until one day, he does. However, since then, Jeong-hee can"t forget the night with Sang-woo and how much better he was than her fiance and starts coming back to his room...