DVMM-145 General Male-Female Monitoring AV: The big-breasted sister and her brother challenge each other to take an aphrodisiac every hour for one hour! As the aphrodisiac effect surges through her body, her sister's reason gradually collapses! She scream

A pair of close siblings were called out on the street and guided to a special studio under the pretense of a survey. 'Take an aphrodisiac every hour and have sex, or you won't win the ¥1 million prize!' They accepted the challenge! Both sister and brother boasted before the challenge, 'There's no way we'll do it!' But as they took the aphrodisiac, the sister's crotch gradually grew hot, transforming her into a lecherous bitch who saw her brother as a stud. The siblings, unable to stop themselves, secretly committed incest while keeping it from their family! The sister, overly sensitive due to the aphrodisiac, convulsed and climaxed repeatedly from her brother's dick! They crossed the sibling boundary and had unprotected sex!