Fumio Kijima was an unassuming student who had an encounter with a self-proclaimed devilish girl. She identified herself as a campaign girl from the demon realm and granted him the power to magically create a room from nothing.
In the beginning, Fumio only used his newfound ability to assist him with his daily tasks, and he didn't want to misuse it. However, one day, his classmates mistreated him, resulting in excruciating pain.
Instead of feeling helpless and crying himself to sleep as he would have in the past, he decided to use his abilities for revenge.
"I'll make them pay for their misdeeds," he thought.
As a result, he began an isolated campaign of imprisonment and manipulation, using his astounding powers to manifest a room and make his objectives a reality.
