Satomi, a diligent female college student, has a boyfriend, but they are both virgins, so they are not able to have sex well. One day, her father's friend, Sakurai-san, who used to dote on Ke'ai when she was little, comes to visit her house and they end up having sex while drunk. Satomi's body and Kokoro are seduced by the skilled caresses of the middle-aged man, and from that day on, she becomes easily aroused, and just seeing an older man makes her fantasise about sex, and she even starts seducing him herself...