Brother Shun'ichi is caught watching adult videos by his older sister Runa, who berates him with harsh insults. Seeking revenge for the humiliation, Shun'ichi plots to secretly film Runa and sell the footage online. When his plan is exposed, Runa begins bullying him relentlessly. Unable to endure any longer, Shun'ichi teams up with his senior, Yanai, to launch a counterattack through forced intercourse. Ultimately, Runa becomes the sex slave of her younger brother and his accomplice. A thrilling tale unfolds as the story progresses with intense, heated developments.