Kazuya, a son, can't contain his excitement when he hears that his mother's friend Minase, who is a radio DJ he always listens to while studying, is coming to stay at their house. However, he is so nervous that he drinks too much and passes out... Minase, who feels affection for Kazuya, Kokoro forces him to kiss her. However, Kazuya loses himself in the secret affair with the woman he admires... The two of them become closer as they have sex many times. However, Kazuya is concerned about Minase, who sometimes has a sad look in her eyes...