When you do, you get Akuro High. A school that is filled to the brim with thugs, gangs, delinquents, and other low lives of society. The story is based in Tokyo, starting off in the shit hole of a school that is run by the four top gangs, each one lead by the Four Kings. They are the strongest students in the school and hold their positions because of their raw power. The students that attend the school for some odd reason or another are absurdly strong, super human in fact such as smashing concrete with their bare hands. However some of these students do have actual powers, powers that they gained from forming contracts with demons.

Demons are peculiar creatures. They are fond with modern human society and the pleasures of it so in order to stay bound to the realm of humans they may form a contract with a human that they are most compatible with. In exchange, the human may gain powers such as fire manipulating though that would be about it. They wouldn't be able to affect the humans physical capabilities unless that was its power or something of that sort.

The beginning would just be a power struggle among the students for the school and territory around Tokyo, but they would soon enter a world completely unbeknownst to them before.