DASS-009 My slender, big-breasted girlfriend was cuckolded and inseminated by my father. - Sumire Kurokawa

Sumire is dating Yosuke with the intention of getting married. - When Yosuke goes to his house to introduce him to his father, he finds out that the person he used to work with as a dad was there. - When Sumire's father suggests that the three of them live together, she accepts the idea, fearing that if she loses her temper, he will reveal her father's activities. - One day after they started living together, Yosuke suddenly had to work and his father, who was left alone with Sumire, put an aphrodisiac in Sumire's drink and pushed her down.