Sana, the older sister, works as a librarian in Tokyo and has come back to her hometown. Sana about her younger brother Keiji, who is all about sports and has no interest in women. She shows off her cleavage and tempts him by saying, "I was going to let you touch it," and her pent-up sexual desire explodes! She uses her strength to capture her and squeezes her huge breasts! She forces him to give her a blowjob, and finally cums inside him in a virgin-free sex session... Just one joke awakens her brother's sexual instincts, and he chases her around the clock, begging for raw sex anywhere in the house...