HUNTC-350 Punishment Game with Big Brother Begins! In this prank, the sister and her friend burst into the older brother’s room, where he is usually treated coldly, and suddenly flash their underwear as part of the challenge. It then escalates further.

His brother is usually treated as gross and repulsive. Then, as a punishment game after losing a game, his younger sister and her friend suddenly barge in and flash their underwear. Things escalate further, with demands to show more intimate parts and to obey, and it eventually leads to sex. At first, the sister and her friend genuinely dislike it. But even while calling it a punishment, the situation gets increasingly heated, and they can’t hide their curiosity about intimate things. In the end, the brother, who was originally just a tool for the punishment game, becomes the best older brother figure who pleases them.