The fourth installment of "Balloon Fetishism" quietly portrays a girl in swimwear playing with balloons in the darkness. The combination of balloons and swimwear heightens the girl's mood while creating a mysterious contrast that stimulates your groin. In a space isolated from the outside world, she touches the balloons with innocent, pure feelings, freeing herself from daily stress and desires—an experience like returning to childhood, offering soothing relief. Yet beyond this lies a sudden, bold scene where the balloon rubs against the girl's sensitive areas. Just like a balloon about to burst, the girl remains capricious, leading to unpredictable developments waiting just ahead.