The timid protagonist Ogawa Ryuu has never been able to stand up for himself, relying on his mother Kyouko and his childhood friend Mami for support while enduring relentless bullying from three girls: Megu, Akira, and Mari. One day, during a particularly violent harassment session, the bullies take things too far and accidentally detach Ryuu's penis from his body. However, something extraordinary occurs: Ryuu can still feel every sensation from his detached organ, and anyone who attaches it to themselves can feel everything as well.

The girls seize this bizarre supernatural opportunity to torment Ryuu further, using his detached equipment as a living sex toy and attaching it to various objects, themselves, and even Ryuu himself. They discover an unexpected hidden cost, as the act of using the detached organ begins altering their personalities, bringing out their deepest and darkest desires. If Ryuu wants any hope of reclaiming his missing body part, he must learn to stop relying on others and finally harness the strange power for himself. The story unfolds as a school-based erotic fantasy with explicit sexual situations, exploring themes of bullying, power dynamics, and supernatural body horror.