The bodies of "younger sisters" trembling on the edge of humiliation and pleasure, gradually growing wet. A pure girl's body slowly matures, taking on the allure of adulthood. 'Moe' is forced to masturbate in her innocent state, 'Aoba' is coerced into sex while wearing her gym uniform, 'Masami' is forced to urinate and then raped by her stepbrother, 'Sakura' loses control and involuntarily pees from sheer terror. Each girl confronts the men's relentless demands, yet cannot suppress the rising impulses within their own bodies. Their experiences are depicted with intense realism.