My parents divorced when I was young, and now that I am an adult college student, I live at my father's house. My biggest problem is Sumire, my father's mistress. One day, Sumire, who works at the hostess club he owns, asks me to take promotional photos of her. As I photograph her, she becomes aroused and kisses me. With no sexual experience, I am bewildered, but she begins teaching me what to do.