15 Years has passed since the 15 hours of darkness, a catastrophic event which shutdown all electronics around the world while the "Hell gates" were open. Before the gates closed monsters emerged from them and provoked even more damage. Now the humanity has begun to rise again, and one of their methods is studying the "Hell Callers", those born during the fifteen hours of darkness within which the remaining creatures from the gates still live.
Follow the attempts of Andrei to survive and stay free as he meet Kaiser and his OP butler, who calls Kaiser "The Emperor".