Mio, who had been working as a model in Tokyo, returned to her hometown after a long absence. Her parents were overjoyed at the reunion, but her younger brother Jun was cold and distant, apparently refusing to go to school and staying cooped up at home. So she teased him, saying, "If you go to school, I'll let you grope my breasts..." But this awakened his dormant sexual desires, and he roughly groped her large breasts, having clumsy sex with her and ejaculating inside. From that day on, she was chased around the clock by her hypersexual brother...
