Kohki, the younger brother, ended up staying at his older brother's house for a while due to training at the head office. One day, he was asked by Akari, who was working out in tight leggings, to help her stretch... As a result, the seam on her buttocks couldn't withstand the pressure and tore open. Unaware that her leggings had split wide open, Akari exposed her bare ass, causing Kohki, who had been sexually frustrated from the training, to lose control of his excitement and suddenly insert his rock-hard cock...
