The older sister, who attends a girls' school, is called "big sister" by her juniors and is loved, but at home she is at the mercy of her shut-in younger brother! The older sister is unable to resist the unlimited creampie sex she receives every day, and her brother, who has had too much sex with her and is tired of her, demands that she "want to do it with another woman!" So she brings a cute junior who admires her home, confesses her lesbian feelings to her, and gives her a deep kiss, putting her at her mercy. The junior girl, who is ecstatic after her older sister confesses her love to her, becomes a sacrifice to her brother who has become a sex beast! Her resistance is futile as she is repeatedly creampied!