DKRA-04203 A condom vs. no-condom challenge project: close college-age siblings take on an inappropriate taboo mission. If the sister can’t reach climax during sex with her younger brother, she’ll win 1 million yen. She can hold back with a condom on, but the moment the condom is removed and they switch to direct contact, she cries out and climaxes immediately. As the tightness intensifies, she won’t let go and continues with repeated finishes. Mariko

Approaching ordinary college-age siblings on the street and inviting them to the studio under the pretense of a relationship survey, we challenged them to a daring mission: in a private room, the siblings would take part in a series of intimate acts, and if the older sister did not climax by the end, they would win a large cash prize. At first, the sister still seemed composed during the protected portion, but once unprotected intimacy began, she was overwhelmed by the intense sensations and writhed in pleasure. The younger brother’s excitement only grew as he watched his curvy, busty sister struggle to hold back her feelings. Please enjoy this forbidden, behind-the-scenes look at the siblings gradually losing control and giving in to their desires. Starring Mariko. This work contains some of the same content as DVDMS-088.