From the back of the book:
This world is being targetted.
The hidden true history.
The world we live in is threatened by the danger of destruction. Enemies called "Emulators" have incaded, breaking through the kekkai surrounding the world. Only you can save it from this danger. Yes, only the "Night Wizards".
Fell the enemies diving into the kekkai.
When the red moon rises in the sky, the common sense we know breaks down and the truth is turned out. The enemies hide in the darkness between tall buildings, in a mirror at night, and in the hearts of humans, waiting for a chance to rewrite the world. The players become "wizards", dive into the laws (kekkai) controlled by the enemies, and destroy them.
Here comes the present day fantasy presented by Takeshi Kikuchi of "Seven Fortress".