Today you are an ordinary high school student who does not like mathematics and often quarrels with arrogant classmates. And tomorrow the bloodthirsty spirit of a higher demon will inhabit the body of your pet. And now you are faced with a difficult task: to help the cruel creation of the lower world and not to die under the flaming blades of the angelic army. But how to figure out where the darkness is and where the light is? After all, the infallible heavenly people will destroy you without hesitation. The demon, on the contrary, promises to grant patronage and protection. However, can he be trusted?