Demonic NTR: The day after having sex with her boyfriend, she was repeatedly penetrated by her sister's husband, who had high sperm count. (Fujii Ranran FSDSS-759)

Fujii Ranran wants to marry her boyfriend, but he's very negative about marriage. She plans to get pregnant before getting married, but lacks confidence that she'll succeed. Then she notices that her older sister has been married for many years and has several children. Her sister didn't get pregnant during her first marriage, but has had several children since marrying her current husband. "Let my stepbrother ejaculate more inside me," she begins a devilish reproductive spree…