Starting from the Second Disease, He Became the BOSS Behind the Scenes.

Ning Xiao is a chuunibyou who can enter the intracranial world anytime and anywhere. And one day, when he casually conceived a daydream about a mysterious organization kidnapping the water class teacher, the mysterious organization really appeared, and everyone took it for granted. When she wonders if she's going to a mental hospital, Vivian, a self-proclaimed Suicide Squad, appears from the sky and accuses him of being the mastermind behind the destruction of her world. If only a beautiful girl came, he would forget it. There were monsters who followed Vivian into his world. As the number of fantasy linkages increased, more diseases, monsters and natural disasters came to his world. These seem to come from his idea of ​​chuunibyou. Helpless, Ning Xiao can only shoulder the mission of saving the world caused by him. The main thing is to show off one's skills at first sight. Monsters from Sword and Sorcery - Recruit magical girls as guides to fight together. Diseases with strange rules - create secret organizations to counteract them. Gradually, Ning Xiao discovered that he was exactly what Vivian said at the beginning, and had become the mastermind behind all kinds of things.