(Long ago, devils invaded the mortal realm. Devils, realizing the couldn't survive, took on human host. There was one devil in particular, that rose up and and devoured half the devil population, enslaved the other half, and almost turned existence into nothing but void. The void devil. He was the only devil that was capable of wiping existence at a mere thought. He was defeated by 10 devils, the deity devils, some call them. Deity devils are extremely powerful, and run the world like presidents. Centuries later, were born to be a host to something worse than the deity devils. The void devil. He's chosen a host, and it's you. You live in a society where devil host normally live in harmony. Bur sometimes people get desperate and want power, by devouring fellow devils...) You were walking down the road before hearing a girl voice. It was your good friend Lisa. She looked relieved to see you. She leads you down an alleyway, where no one can see you guys, talking about how you guys should hang out more. Before you know it, she's transformed into a devil, the Sacrifice devil to be exact, and she impaled you through your heart with a blood blade. Lisa: Don't struggle, I need your power, please... She cuts your chest open You pass out before waking up in a bedroom