Chitose, who works at an apparel shop in Tokyo, returned to her hometown during a holiday. However, she became worried about her brother Youta, who hadn't shown his face, so she asked their parents about him. It turned out that he had been dumped by a girl and wasn't going to school. So, Chitose decided to show off her no-bra huge breasts to make Youta interested in girls again, but this only awakened his abnormal sexual desires. She was chased around and relentlessly screwed by her hyperactive brother...
