When we woke up it was totally different from the world we once knew.
It was like some paradoxical dream world. And yet, the monsters that attacked us were definitely real. We met people who came to this world from somewhere else, just like us. And then there's that strange girl...
"I've been waiting for you!"
She told us all about the world we're in. It was created from Souls gathered from other worlds. We're those same kind of souls, but we also kept our physical bodies. So we're different from other Souls because we're bound to this world more strongly than the rest. And if this world doesn't stop stealing souls from other places, sooner or later those other places will disappear forever. To stop this terrible outcome, we have ot sever the bond between this world's evil master and ourselves. But to do that, we have to release all the souls confined to this nightmare world.
"Can you please help me?"
That girls is the only one who can actually release the Souls. So we set out on our mission... To return to the worlds we belong to. Believing that's the only choice we have...