Eren, a college student in Tokyo, returns to her hometown after a long time but finds it difficult to communicate with her teenage brother, feeling a bit lonely. One day, while偶然 finding herself in her brother's room, Eren, as she did in her childhood, teases him by showing off her braless, ample breasts. However, this awakens her brother's dormant sexual desire. He aggressively fondles her breasts and penetrates her, leaving her helpless as he repeatedly ejaculates inside her. From that day on, she is relentlessly pursued by her extraordinarily virile brother...
