A girl who calls herself a demon appeared before Fumio Kijima, a timid student. This mysterious girl claimed to be an emissary from the demon world and bestowed upon him an extraordinary ability—the power to "summon a room" out of thin air. Initially, Fumio used this newfound power responsibly, finding it useful in his daily life without any malicious intent.
However, one day, his classmates falsely accused him and bullied him mercilessly, causing him immense suffering. In the past, Fumio would have succumbed to despair, crying himself to sleep in anguish. But now, with his supernatural power at his disposal, things were about to change. "I will make them regret it!" he declared.
Using his ability to summon his "room," Fumio embarked on a dark journey of confinement and brainwashing. His goal was clear: to exact revenge on those who wronged him. Thus began his reign of manipulation and control, fueled by the power bestowed upon him by the enigmatic demon girl.

