Hibiki reluctantly agrees to help her brother Shuji with his research, but his assistance quickly becomes a manipulative seduction. Trapped by a concoction that stirs her deepest, most forbidden desires, Hibiki succumbs to Shuji’s relentless advances. Through binding and intimate play, he awakens a dark, passionate obsession within them both, blurring the lines between sibling loyalty and profound, intoxicating lust.